# Forum Home Renovation Kitchens  what fittings to use to join 2 bench tops together??

## wozzzzza

I have a laminated 33mm kitchen bench, extending it with another piece of laminated 33mm top, what fittings do I use to join them together tightly??

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## Random Username

Prestige 65mm Bench Top Connector - 2 Pack I/N 4010372 | Bunnings Warehouse

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## OBBob

Random has posted the right connectors but just keep in mind you need the holes bored in the bottom of the bench to accept those (it's not clear from your post if these two bit of bench were manufactured to go together or you are just using up things you had).

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## METRIX

I don't like how the forum allows for Random Username, IMO you should have to have a name assigned to the user.

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## Bedford

> I don't like how the forum allows for Random Username, IMO you should have to have a name assigned to the user.

  It is. 
No-one else can use it.

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## OBBob

> I don't like how the forum allows for Random Username, IMO you should have to have a name assigned to the user.

  You need to include a smiley to show you're joking.  :Smilie:

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## METRIX

> You need to include a smiley to show you're joking.

  Why would I be joking ? If you have something to add why not have a name, we all have names, even just a simple number to distinguish the comment.
When I say hello to my neighbor I use their names, I don't say hi Random Neighbor how are you today, or when I see my family I don't say Hello Random Sister  :Rolleyes:  
Although on one job I do have a Random Wife but that's another story  :Biggrin:   :Wink:

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## OBBob

> Why would I be joking ? If you have something to add why not have a name, we all have names, even just a simple number to distinguish the comment.
> When I say hello to my neighbor I use their names, I don't say hi Random Neighbor how are you today, or when I see my family I don't say Hello Random Sister  
> Although on one job I do have a Random Wife but that's another story

  
Fair enough ... how's the 'signature test' coming along? Any results or preliminary findings?  :Smilie:

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## wozzzzza

> Prestige 65mm Bench Top Connector - 2 Pack I/N 4010372 | Bunnings Warehouse

  thanks, that was what I was looking for but didn't know their name and google didn't tell me.

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## METRIX

> Fair enough ... how's the 'signature test' coming along? Any results or preliminary findings?

  Ahh Signature Yes I need to fix that.

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## METRIX

> thanks, that was what I was looking for but didn't know their name and google didn't tell me.

  Wozzzzza, you need to get a new Google, I typed benchtop joiners and got the following as first hit.  :Rolleyes:

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## phild01

If you get the prestige ones (cheaper, Kaboodle is a rip-off),  I would get two packs (4) as I would use 3 as a minimum.  If you have a router it will be useful making the underbench keyholes.

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## wozzzzza

will do. I got router and forstner bits
thanks.

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## METRIX

> Kaboodle is a rip-off

  No disagreement there, but he still needs a new Google  :Biggrin:

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## Random Username

There you go - I've added my old avatar just for you...

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## renov8or

While we are on the subject of joining bench tops what is the best way to prevent water getting into the join and swelling the HMR. I have done 2 kitchens and applied silicon sealer (basic clear) to the entire surface of both edges and clamped them together and wiped away the excess only to have them swell when moisture got in a after a couple of years - in areas where water may often lay like around the sink etc. I clamped them together when silicon was still wet, the first time I thought I may have played around with getting the edges lines up 100% for too long and the silicon might have started to go off, but the second time I made sure I was quicker but made no difference. What is the secret?

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## peterlonz

> While we are on the subject of joining bench tops what is the best way to prevent water getting into the join and swelling the HMR. I have done 2 kitchens and applied silicon sealer (basic clear) to the entire surface of both edges and clamped them together and wiped away the excess only to have them swell when moisture got in a after a couple of years - in areas where water may often lay like around the sink etc. I clamped them together when silicon was still wet, the first time I thought I may have played around with getting the edges lines up 100% for too long and the silicon might have started to go off, but the second time I made sure I was quicker but made no difference. What is the secret?

  I honestly don't think there is a secret.
From my own observations, laminate benchtops are very prone to water ingress over time if water is allowed to lay around.
Generally joins are made well away from the area surrounding the (wet area) sinktop, which is generally stainless.
If this were my problem I think I would attempt to seal the particle board faces with epoxy resin, allow maybe one hour & then bring the faces together with the proprietry clamps that have been discussed here already. This should yield a strong joint & a waterproof joint.
One caveat however: the HMR particle board gains its limited water resistance by the inclusion (as I understand things) of waxes. Potentially this could limit the effectiveness of glue or epoxy or any over protective coating. So perhaps best to first do a small experiment?

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## abscraig

> I have a laminated 33mm kitchen bench, extending it with another piece of laminated 33mm top, what fittings do I use to join them together tightly??

  I would stay away from the bigger hardware stores, try a Cabinetmaker they will be buying them for around 20c each.

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## Random Username

The best way to exclude moisture is to coat the exposed ends with a few coats of marine epoxy (coat... give it 2-3 hours... another coat... 2-3 hours... another etc) then one final coat just before doing the final assembly.  You want to do recoating while the epoxy is still green and chemically active, not a day later when you'll need to sand it to get the next coat to stick.

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## arms

> While we are on the subject of joining bench tops what is the best way to prevent water getting into the join and swelling the HMR. I have done 2 kitchens and applied silicon sealer (basic clear) to the entire surface of both edges and clamped them together and wiped away the excess only to have them swell when moisture got in a after a couple of years - in areas where water may often lay like around the sink etc. I clamped them together when silicon was still wet, the first time I thought I may have played around with getting the edges lines up 100% for too long and the silicon might have started to go off, but the second time I made sure I was quicker but made no difference. What is the secret?

  using basic silicone will not achieve a water seal in the joints ,silicone comes in many different classes ,the basic silicone goes hard over time and allows water to pass it .
for benchtop joints you need to use roof and gutter or plumbers silicone .
this type stays fluid permanently and wont let water pass .
and as an after thought most swelling of the joints are from people boiling the jug over the joint without really thinking about whats below the jug .
let the abuse begin !!

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## abscraig

I agree, the correct silicone is the best thing to use.

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## renov8or

> using basic silicone will not achieve a water seal in the joints ,silicone comes in many different classes ,the basic silicone goes hard over time and allows water to pass it .
> for benchtop joints you need to use roof and gutter or plumbers silicone .
> this type stays fluid permanently and wont let water pass .
> and as an after thought most swelling of the joints are from people boiling the jug over the joint without really thinking about whats below the jug .
> let the abuse begin !!

  Ahhhh!! So so that is the difference between normal silicon and roof/gutter/plumbers silicon, I did not know. The biggest difference I could see is acidic cure or not, and I sometimes have plumbers silicon.....and possibly used. You are right with the kettle boiling over for the problem with my second kitchen, but a rental so what can you do, and possibly was only one tenant.

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## phild01

Never had silicone go hard...acetic or neutral cure.  The very first silicone I ever used was Dow Corning acetic cure pre-cartridge days back in the early 70's.  It never went hard as I recall.

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## arms

> Never had silicone go hard...acetic or neutral cure.  The very first silicone I ever used was Dow Corning acetic cure pre-cartridge days back in the early 70's.  It never went hard as I recall.

  sorry but contrary to what you recall ,the facts back up the differences in silicone types .if there wasn't any discernible difference between types then there wouldn't be a need for different types, would there ??

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## joynz

> sorry but contrary to what you recall ,the facts back up the differences in silicone types .if there wasn't any discernible difference between types then there wouldn't be a need for different types, would there ??

  it's actually common to devise new names for products that are basically the same thing - standard marketing practice to attract different consumer targets. 
Looking up the Fullers range (came up first in Google) the first eight or so silicones I looked at (including plumbers, bathroom, paintable etc)  all state 'permanent 25% flexibility' 
The info on the Fullers' plumbers silicone difference seems to be more related to being non corrosive to metal roofs,  OK for contact with drinking water and uv stable rather than being more flexible.

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## arms

> it's actually common to devise new names for products that are basically the same thing - standard marketing practice to attract different consumer targets. 
> Looking up the Fullers range (came up first in Google) the first eight or so silicones I looked at (including plumbers, bathroom, paintable etc)  all state 'permanent 25% flexibility' 
> The info on the Fullers' plumbers silicone difference seems to be more related to being non corrosive to metal roofs,  OK for contact with drinking water and uv stable rather than being more flexible.

  and we are not talking about flexibility we are talking about the product breaking down over time and letting moisture past itself ,but that's excluding the nongs that don't know better or don't care as its not their property .

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## renov8or

I think the problem is the adhesiveness of the silicon to the HMR bench top. If it was metal, glass or ceramic tile the problem would not occur. As a properly clamped bench top joint does not move the flexibility should not be an issue, and as minimal silicon remains once the bench tops are tightly clamped there is little to flex anyway, unlike having a 1-2mm layer. As mentioned earlier the treatment to resist water is probably the reason for not adhering 100%. It would probably adhere to normal timber better. Epoxy glue/resin as mentioned also may seal it better, but if you ever had to dismantle a bench you would likely break some of the HMR edge away, although the Laminex upper surface should be ok as it is stronger. And a few coats of epoxy would build up the edge ever so slightly and prevent a perfect butt joint. Possibly some epoxy glue/resin/marine Araldite along the top 5-10mm of the joint when installing might be best.

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## skoorbs

The only difference between plumbers silicon and the rest is the acid vs neutral cure. Roofing silicon is neutral. Neutral is for metal. Acid is for everything else as it will etch into the substrate, creating a stronger bond. This is no good for metal as it will etch into the coating (paint, powder coat, gal. etc) and encourage rust by exposing the area to oxygen. 
I could be wrong but silicon is the worst thing to use in this case. The timber will always absorb certain amount of moisture without total sealing; with epoxy or bench paint, whatever. Best to seal the ends and (try to) keep the joint well away from any area when water will sit for any amount of time. Then clear coat entire bench (if you want wood-grain) or stain/paint etc. Might be better off with some sort of biscuit join or whatever.....

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## skoorbs

> sorry but contrary to what you recall ,the facts back up the differences in silicone types .if there wasn't any discernible difference between types then there wouldn't be a need for different types, would there ??

  Silicon is silicon. Neutral or acid cure. None stay "liquid". None go "hard". All will eventually perish, the speed and severity dependent on the application. Most are good for 10-20 years. It is  rubber. There are different qualities, applications, and brands (and combinations), but  it is all essentially the same stuff. Don't believe everything written on the label or said by the Bunnings floor staff..
For general maintenance around the house, the cheapest $2 stuff is as good as the $12 Sika stuff..

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## Random Username

Go the whole hog - route the board back by 2-3 mm on each side, leaving just the laminate sheet sticking out, form a dam around the board with duct tape, fill your 2-3mm deep hole with epoxy resin, let it cure, route a whisker of the full board and laminate off to even it all out and reassemble, safe with the knowledge that there's now no wood to swell at the joint interface!

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## phild01

> Go the whole hog - route the board back by 2-3 mm on each side, leaving just the laminate sheet sticking out, form a dam around the board with duct tape, fill your 2-3mm deep hole with epoxy resin, let it cure, route a whisker of the full board and laminate off to even it all out and reassemble, safe with the knowledge that there's now no wood to swell at the joint interface!

  Is this something you have successfully tried?
 Mason's mitres are done to precision.  Clamping anything less risks buckling the laminate.

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## skoorbs

As long as your cuts are straight and square you'll be right. Most kitchen bench-tops are chipboard anyway.. Not the most water tight stuff to start with.
I checked mine and over a 400-odd mm join it has like 6 of those clamps. Do that, then clear coat the top; done.

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## phild01

> As long as your cuts are straight and square you'll be right. Most kitchen bench-tops are chipboard anyway.. Not the most water tight stuff to start with.
> I checked mine and over a 400-odd mm join it has like 6 of those clamps. Do that, then clear coat the top; done.

  Surely you are not clear coating the laminate!

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## Random Username

> Is this something you have successfully tried?

  Nup.  Just a thought about how far you could actually go to create a 'perfect' solution.  But I don't think I'd have any problems successfully and accurately re-doing a mason's mitre if I had done one in the first place.  (I've actually been meaning to make a mason's mitre template one day, but that day will have to wait till I need to actually make a mason's mitre). 
I'd be much more worried about cutting so close to the back side of the laminate with a long-ish bit and the router potentially unsupported for half it's base diameter.  The slightest rocking motion and you could be through the laminate.

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## arms

> Nup.  Just a thought about how far you could actually go to create a 'perfect' solution.  But I don't think I'd have any problems successfully and accurately re-doing a mason's mitre if I had done one in the first place.  (I've actually been meaning to make a mason's mitre template one day, but that day will have to wait till I need to actually make a mason's mitre). 
> I'd be much more worried about cutting so close to the back side of the laminate with a long-ish bit and the router potentially unsupported for half it's base diameter.  The slightest rocking motion and you could be through the laminate.

  god help us ,do any of you guys actually do this type of work for a living ,or are you just armchair warriors trying to make simple jobs harder to figure out how to make them easier .

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## justonething

> god help us ,do any of you guys actually do this type of work for a living ,or are you just armchair warriors trying to make simple jobs harder to figure out how to make them easier .

   Nope. otherwise I'll go on the Specialty Trades - Contractor Talk - Professional Construction and Remodeling Forum

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## Random Username

> god help us ,do any of you guys actually do this type of work for a living ,or are you just armchair warriors trying to make simple jobs harder to figure out how to make them easier .

  Nope, I just get to do patch up jobs for family and friends where the trade approach has either failed or is either 'nah, can't do anything to fix that, you need a new one, which'll be a day's work to install on top of the price of a new one,' or 'Λυπάμαι, δεν μπορώ να μιλήσω αγγλικά'. 
I [S]sometimes[/S] frequently use overkill solutions on my own stuff, though.

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## skoorbs

> Surely you are not clear coating the laminate!

  No.. Had to re-read OP's original post. I automatically assumed he meant timber laminates, as opposed to laminated timber, such as this one: 2100 x 900mm 30mm Laminated Clear Pine Panel I/N 0290007 | Bunnings Warehouse
I only jumped to that conclusion 'cos I'm gonna do same thing in my laundry!! Sorry about that..
Oh well; same advice without the clear coat: get it cut properly!

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## skoorbs

It's just cut and clamp, regardless of finish.. If really paranoid about  water in the join, coat the ends with epoxy then clamp together  immediately; don't let dry or he'll get a gap. Plain old wood glue would  probly be better still..it's thin enough to be easily forced into  particles (can use more), which also makes it easier to clean excess  while wet.   

> god help us ,do any of you guys actually do this type of work for a living ,or are you just armchair warriors trying to make simple jobs harder to figure out how to make them easier .

  I thought these  forums (fora?) were to bounce ideas and info around among like-minded  enthusiasts.. And I find it difficult to believe an actual, professional  cabinet maker would advise using silicon...

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## Eden

Dont forget that all the "environmentally green" freaks using vinegar as a cleaning product are causing the break down of silicon and starting mould ingress. 
you would also be surprised with what happens in a rental property !  
cheers Eden

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## phild01

> Dont forget that all the "environmentally green" freaks using vinegar as a cleaning product are causing the break down of silicon and starting mould ingress. 
> you would also be surprised with what happens in a rental property !  
> cheers Eden

   Something I didn't know about vinegar and silicone.  I'll have to try that with a lump of silicone in a jar of vinegar.

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## arms

> It's just cut and clamp, regardless of finish.. If really paranoid about  water in the join, coat the ends with epoxy then clamp together  immediately; don't let dry or he'll get a gap. Plain old wood glue would  probly be better still..it's thin enough to be easily forced into  particles (can use more), which also makes it easier to clean excess  while wet.   
> I thought these  forums (fora?) were to bounce ideas and info around among like-minded  enthusiasts.. And I find it difficult to believe an actual, professional  cabinet maker would advise using silicon...

  and pray tell what do you use in your kitchen installations

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## renov8or

> Dont forget that all the "environmentally green" freaks using vinegar as a cleaning product are causing the break down of silicon and starting mould ingress. 
> cheers Eden

  I did not realise vinegar affected silicon, I thought it would be less damaging than bleach. I was told by a shower screen installer never to use Bam as its strong chemicals would damage silicon.   

> you would also be surprised with what happens in a rental property ! cheers Eden

  No I wouldn't, and always suspicious if something "breaks"  :Rolleyes:

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## skoorbs

"and pray tell what do you use in your kitchen installations" 
Silicon is a sealant, not an adhesive. Silicon around the sink, toilet base, shower recess, roof/gutter touch-up (neutral only) etc.
Appropriate glues for fixing.. wood glue, liquid nails, epoxy. It is not used to provide structural strength.  https://youtu.be/iBmyFtGg0Iw - specifically says wood glue, NOT silicon. Good old Bunnings seems to agree - How to Install a Laminate Benchtop | Bunnings Warehouse 
Silicon does NOT stay liquid, plumbers type or not. It is not a water-proofing cure-all. It remains flexible, and some have a greater range of flexibility, depending on the application, to allow for expansion, structural movement etc. Pretty handy stuff. But don't believe me - ask any roofer or plumber or carpenter or waterproofer. Pretty common knowledge in (and out of) the construction industry, I would say.. 
I, pray, take it from your reply and the link to your website that you  are a cabinet maker, or run a cabinetry workshop.. If you use silicon to hold everything together then  good luck to your customers.

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## arms

If you use silicon to hold everything together then  good luck to your customers. 
I never said anywhere that I use silicone to hold anything together ,I said quite clearly to use plumbers silicone in the joint .
has worked for me for nigh on 30 years now and the only warranty claims that I have ever had is from people boiling the jug over the sealed joint , easy to see as it leaves 2 raised sections in the joint .
but you go ahead and believe the bunnings utube sideshow .
bothers me naught .
I know what works .you may know diddley squat , dunno, you have yet to prove your self.

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## r3nov8or

Just checked my benchtop joint. My guy used 4 of the benchtop connectors. There is also no evidence on the underside of any squeeze out of anything at all, although I am almost positive epoxy was used at the upper edge. Our kettle has been boiled over the join for, oh, about 12 years. No issues at all.

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## r3nov8or

I also read the start of the thread and complaints about 'random' usernames. How about those losers that use numb3r5 in place of letters! Crazy buggers...

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## arms

> Just checked my benchtop joint. My guy used 4 of the benchtop connectors. There is also no evidence on the underside of any squeeze out of anything at all, although I am almost positive epoxy was used at the upper edge. Our kettle has been boiled over the join for, oh, about 12 years. No issues at all.

  congratulations

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## r3nov8or

> congratulations

  To my kitchen maker, yes. Also respect to the local benchtop manufacturer, who has a lot more to lose than Chinese makers.

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## Eden

was one of the many  quotes or posts to me ? 
been working too hard lately
whoops sorry  
2 part epoxy is the best 
next  
silicone or external aquadhere/woodworkers glue 
not the expanding crap they sell 
external bondall or aquadhere is good but needs trimming with a sharp blade and is shorter term 
10ish years  --- 2 part epoxy
5 yrs --- silicone
2 yrs glue  
it also depends on the cut of the join   :Wink:  
thats where experience comes into play 
cheers Eden

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## r3nov8or

sorry for the hijack, but maybe an *admin* can help. I can't see the latest posts of this thread. When I try to go to the end, the first page is displayed. For me it says I have 3 pages, but I can only go to pages 1 and 2. For this reason I won't be able to see any responses to this post, so please PM if you need me to try something. Every other thread is working fine for me.

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## r3nov8or

> sorry for the hijack, but maybe an *admin* can help. I can't see the latest posts of this thread. When I try to go to the end, the first page is displayed. For me it says I have 3 pages, but I can only go to pages 1 and 2. For this reason I won't be able to see any responses to this post, so please PM if you need me to try something. Every other thread is working fine for me.

  Must have been a browser problem. As you were  :Smilie:

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## renov8or

> was one of the many  quotes or posts to me ? 
> been working too hard lately
> whoops sorry  
> 2 part epoxy is the best 
> next  
> silicone or external aquadhere/woodworkers glue 
> not the expanding crap they sell 
> external bondall or aquadhere is good but needs trimming with a sharp blade and is shorter term 
> 10ish years  --- 2 part epoxy
> ...

  This raises another point. Should the benchtop be glued or just sealed to prevent water getting into the join - I thought just the latter and being the reason I have used silicon sealant in the past. Not sure who told me to use silicon, or whether I saw someone use it? I have only used the basic joiners as in Kaboodle photo in previous post as this is how the bench was cut and prepared for DIY install. I would not have expected that the bench would need glueing as the joiners hold it tight and then it is screwed to the carcass of the cabinets to hold in place. If glued that would prevent a problem if you ever had to dismantle for some reason - floor repairs, plumbing etc.

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## justonething

> This raises another point. Should the benchtop be glued or just sealed to prevent water getting into the join - I thought just the latter and being the reason I have used silicon sealant in the past. Not sure who told me to use silicon, or whether I saw someone use it? I have only used the basic joiners as in Kaboodle photo in previous post as this is how the bench was cut and prepared for DIY install. I would not have expected that the bench would need glueing as the joiners hold it tight and then it is screwed to the carcass of the cabinets to hold in place. If glued that would prevent a problem if you ever had to dismantle for some reason - floor repairs, plumbing etc.

  Yes, sealing the joint is important. However, even the best sealant needs a gap for it to do its job properly. If you really want sealant to work the way its meant to, you first spread the sealant, and put a 1mm spacer in between the two bench top and tighten it so that excess sealant will come out on both side of the joint, but leave the 1mm gap. The sealant, unlike adhesive, likes to bond with each other more than the substrate. After 1 day or so once the sealant is cure, then you can proceed to tighten joint to close as much of the gap as possible.  This is the same way we use to silicone as gasket. You will no doubt get a very water tight joint. But there might be a small gap though. 
If you don't want gap then, then silicone wouldn't be the best substance to use in my view. On the other hand, PVA has high adhesive ability as it forms strong bond between fibers but chipboard is porous so the the joint wouldn't be very strong. but if you use a water proof variety like titebond 3 and spread it liberally no both sides of the joint, (not like the guy in bunnies does it on his video), wait for 5 mins so the pores in the chipboard absorb as much glue as it needs, then clamp it together. Then you will have no gap as well as a water resistant joint. 
Of course, epoxy is the best glue to use by far. But the others will be adequate if it is done properly.

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## CuttingEdgeKitchens

> If you don't want gap then, then silicone wouldn't be the best substance to use in my view. On the other hand, PVA has high adhesive ability as it forms strong bond between fibers but chipboard is porous so the the joint wouldn't be very strong. but if you use a water proof variety like titebond 3 and spread it liberally no both sides of the joint, (not like the guy in bunnies does it on his video), wait for 5 mins so the pores in the chipboard absorb as much glue as it needs, then clamp it together. Then you will have no gap as well as a water resistant joint. 
> Of course, epoxy is the best glue to use by far. But the others will be adequate if it is done properly.

  I have been building kitchens for 20 years and have always used silicon on my joins and cut outs. 
Never had one swell or any issues with silicon!!!

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## renov8or

But how many do you see again? My problems are 2/2 kitchens, 2/3 joins. 
PPOR - 2 joins in U shaped kitchen with sink in the middle under window. One join is 300mm from sink and running away to side wall, no problem as a dryish area. The other is in line with the sink drain tray end and just within cutout so only a small section in front and behind the sink is visible but has some swelling which I have minimised by a minute/almost invisible build up of silicon over the joins to prevent more water getting into them. When delivered I questioned the kitchen company about the location of the right join at end of sink and I was told it was put here rather than mirrored location to other join to minimise exposed join. Fair enough, only about 100mm of join visible instead of 600mm but at a very vulnerable location. I would have assumed and preferred 600mm join visible and starting 100mm from sink and running away to side wall. 
IP - one join in L shaped kitchen with sink under window, join 100mm away from sink and running away to side wall. Dry location identical to problem free join in PPOR but where a tenant had a jug located and where swelling has occurred. 
All joins done in same way.  
Dry area joins, as in away from where water is likely to be other than a wipe down is probably never an issue. I doubt if some installers even use any silicon, joins are so tight you could hardly see with a magnifying glass.

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## METRIX

> Silicon is a sealant, not an adhesive. .

  That's not technically correct, there are plenty of Silicon Adhesives on the market.
Admittedly Silicon has a lower adhesive strength than say a construction adhesive but it is still technically recognized as an adhesive. 
The bonding of modern car windows and windscreens is done with silicons, these are 2 part silicons which ave a stronger adhesive over 24 hours after application.
If these did not have adhesive properties there would be an awful lot of windscreens popping out in the newer style cars which don't use rubber seals. 
Such as  
Selleys 401 RTV Silicone 401 RTV | Selleys Australia 
Bostik 922 RTV Bostik Australia :Industry - Catalogue - Bostik RTV 922 Industrial Silicone 
Locktite Superflex RTV Loctite ® Superflex ® RTV, Clear Silicone Adhesive Sealant - Loctite 
Permatex RTV Sealants : Permatex® Clear RTV Silicone Adhesive Sealant

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## METRIX

Looking at Think Timber Bench tops installation guide, they recommend Silicon between the joins and they manufacture the benchtops.

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## phild01

> That's not technically correct, there are plenty of Silicon Adhesives on the market.
> Admittedly Silicon has a lower adhesive strength than say a construction adhesive but it is still technically recognized as an adhesive. 
> The bonding of modern car windows and windscreens is done with silicons, these are 2 part silicons which ave a stronger adhesive over 24 hours after application.
> If these did not have adhesive properties there would be an awful lot of windscreens popping out in the newer style cars which don't use rubber seals. 
> Such as  
> Selleys 401 RTV Silicone 401 RTV | Selleys Australia 
> Bostik 922 RTV Bostik Australia :Industry - Catalogue - Bostik RTV 922 Industrial Silicone 
> Locktite Superflex RTV Loctite ® Superflex ® RTV, Clear Silicone Adhesive Sealant - Loctite

  I believe for windscreens polyurethane is used like Sika 255, but yes silicone is often used as an adhesive in glazing e.g. shower screens or commercial frameless windows.
  I use it to stick aluminium together.

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## METRIX

I read that Dow Corning Betaseal U418 is the choice of majority of car manufacturers nowadays. 
When you think of a windscreen it not only has to stay there when subjected to 100+ kph winds for years, but must not pop out when its smashed with Airbags in an accident.

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## phild01

..and the bonded screens in a vehicle is a factor in total body strength.

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## CuttingEdgeKitchens

> But how many do you see again? My problems are 2/2 kitchens, 2/3 joins. 
> PPOR - 2 joins in U shaped kitchen with sink in the middle under window. One join is 300mm from sink and running away to side wall, no problem as a dryish area. The other is in line with the sink drain tray end and just within cutout so only a small section in front and behind the sink is visible but has some swelling which I have minimised by a minute/almost invisible build up of silicon over the joins to prevent more water getting into them. When delivered I questioned the kitchen company about the location of the right join at end of sink and I was told it was put here rather than mirrored location to other join to minimise exposed join. Fair enough, only about 100mm of join visible instead of 600mm but at a very vulnerable location. I would have assumed and preferred 600mm join visible and starting 100mm from sink and running away to side wall. 
> IP - one join in L shaped kitchen with sink under window, join 100mm away from sink and running away to side wall. Dry location identical to problem free join in PPOR but where a tenant had a jug located and where swelling has occurred. 
> All joins done in same way.  
> Dry area joins, as in away from where water is likely to be other than a wipe down is probably never an issue. I doubt if some installers even use any silicon, joins are so tight you could hardly see with a magnifying glass.

  All my work is for customers on the northern beaches of Sydney, trust me if there was an issue with the bench top swelling they would call me!!! 
I have used this method since I was an apprentice with zero return/problem rate!!  
Are you sure they used silicone?? A lot companies don't!!  
The sink and cooktop cutout should also be silicone. 
Another issue is what is used between a tiled splashback and the bench top. Some rough tilers will just grout it which allows water to penetrate the back edge of the bench top. This join should always be silicone!!!

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## renov8or

> All my work is for customers on the northern beaches of Sydney, trust me if there was an issue with the bench top swelling they would call me!!!

  Hey, what are you saying ;-)   

> Are you sure they used silicone?? A lot companies don't!!  
> The sink and cooktop cutout should also be silicone. 
> Another issue is what is used between a tiled splashback and the bench top. Some rough tilers will just grout it which allows water to penetrate the back edge of the bench top. This join should always be silicone!!!

  Yeah pretty sure as I did it myself, twice ;-). Covered both edges and rubbed it well in to penetrate every nook and cranny. 
Did same on sink (and under sink lip) and cook top cutouts, silicone at back of bench/splashback tiles, no grout used, no problems there. 
I think it just comes back to if in a vulnerable position where water may lay. Being aware of problem after first kitchen I was super careful with second and trying to line up/clamp quicker in case silicon had started to go off the first time. No diff, same problem. Next time I might coat both edges with epoxy and rub well in to try and seal the cut edge without building up proud, let dry and then silicon when joining.

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## phild01

> Next time I might coat both edges with epoxy and rub well in to try and seal the cut edge without building up proud, let dry and then silicon when joining.

  I'd only attempt this after doing it after a trial run.  You may end up with a gap in the laminate.

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## r3nov8or

This is where my most recent benchtop came from > http://www.newgrovebenchtops.com.au/ 
Check the video tutorial page for their recommended install method. (Glue, and "no need for silicone")

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## METRIX

> A 
> Another issue is what is used between a tiled splashback and the bench top. Some rough tilers will just grout it which allows water to penetrate the back edge of the bench top. This join should always be silicone!!!

  Yeah, see this all the time, and the grout has cracked and fallen out, around the normal part of benchtop no so much of a problem, but around the sink is a big NO NO.
Same as in bathrooms I see the floor to wall, and wall to wall joins grouted by some tilers, these should be silicone to allow for slight movement, especially in shower recesses.

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