# Forum Home Renovation Doors, Windows, Architraves & Skirts  What do I use to replace rotten wood??

## GraderL

In an earlier post I recommended Earl's Wood Hardener and Selleys Liquid Nails Waterproof for repairing rotten wood in window frames. https://www.renovateforum.com/f84/wh...n-wood-113560/
This original post has been archived so there is no ability to add comments to it. 
Note that the excellent Selleys Liquid Nails Waterproof is no longer produced. 
The replacement Selleys Liquid Nails Rapid Cure is totally unsuitable for this application.  After reviewing Rapid Cure I have found that it is a good adhesive but has the following issues:
1.  It is a clear adhesive so is very difficult to see and to control placement during application, resulting in blobs and uneven thickness of application (Waterproof is beige and easily seen).
2.  Rapid Cure is quite thin compared to Waterproof making it difficult to bridge gaps, use as a gap filler, or to build up on the surface to replace missing timber.
3.  Rapid Cure sets too quickly giving very limited working time and the adhesive builds up on application tools.  It is very difficult to clean set adhesive off application tools.  By comparison Waterproof has a long working time and tools can be scraped off during use, then easily cleaned with turps.
4.  Waterproof sands very well giving an excellent smooth surface, but set Rapid Cure is more flexible and moves with the sander so does not sand.  It just leaves a mess and it is impossible to achieve a smooth surface. 
Some stores may still have stock of Waterproof.  I managed to get some online from Supercheap Auto. 
I would like to see Waterproof reintroduced, ideally with less expansion during setting so there is less material to sand back to achieve a flat surface. 
Overall it is difficult to understand why Selleys replaced their excellent Waterproof product which is so versatile as an adhesive and gap filler with the inferior Rapid Cure which can only be used as an adhesive.

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## joynz

Just use Builder's Bog.

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## phild01

> In an earlier post I recommended Earl's Wood Hardener and Selleys Liquid Nails Waterproof for repairing rotten wood in window frames. https://www.renovateforum.com/f84/what-do-i-use-replace-rotten-wood-113560/#post965857
> This original post has been archived so there is no ability to add comments to it.

  You mean this: https://www.renovateforum.com/f84/wh...n-wood-113560/

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## GraderL

Thanks plild01.  I've edited the hyperlink so it now works. 
As far as builders bog is concerned, painters use it so the job looks good when they get paid.  Then over time it shrinks and pulls away from the timber opening up cracks, and thin sections of it crack because it is brittle.  Water gets in through the cracks and the rot continues. 
I had a carpenter replace rotted sills on celestial windows (vertical windows over the middle of a room).  He removed the rotted timber and bolted a new sill piece back to the solid timber of the original sill, using builders bog to fill the gap between the two pieces of timber.  After a while water started pouring into the house during storms.  This happened repeatedly before I finally realised that the builders bog had pulled away from the timber and was allowing the water in.  The paint was the only thing trying to prevent water entry, and any cracks in the paint due to timber movement allowed water to pour into the house. 
From my experience with builders bog, it is totally unsuitable for exterior window repairs.

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## Marc

Best fix is to replace the window.  :Smilie:

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## ifhaun

I was going to ask if you had tried Nordsjo Super Filler. Water based, exterior, some flexibility, sands well, stores well. No adhesive properties though. For some reason, it's discontinued, according to their website (perhaps because Bunnings no longer seems to carry anything by Nordsjo). 
Yes bog is totally unsuitable for exterior wood. I don't know whether bog shrinks or not, but in any case wood moves and bog doesn't. 
Edit: Selleys Aquadhere Durabond mixed with sawdust might be worth a try.
There's also Selleys Pro Series Adhesive/Sealant which is sandable, according to Selleys (possibly they have just rebranded the stuff you like?) http://www.selleys.com.au/adhesives/...hane-adhesive/

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## GraderL

> I was going to ask if you had tried Nordsjo Super Filler. Water based, exterior, some flexibility, sands well, stores well. No adhesive properties though. For some reason, it's discontinued, according to their website (perhaps because Bunnings no longer seems to carry anything by Nordsjo).

  I think this is the "Swedish filler" that a painter used on my house some years back.  It is a white material with a grainy structure, and is quite light when set as opposed to builders bog which is comparatively heavy.  While this is a good waterproof filler, it doesn't hold the timber together so any splits just open up and water gets in to rot the timber. Another product like builders bog that looks good when the painter gets paid. 
When I contacted Selleys technical department recently I was advised that they do not have a replacement for Liquid Nails Waterproof that can be used for repairing windows.  I tried their latest Liquid Nails Rapid Cure and it was a disaster as it was difficult to apply and virtually impossible to sand.  Selleys Pro Series Adhesive/Sealant may be worth a try but I am concerned that it is advertised as a flexible sealant.  My experience is that many products are advertised as sandable but they are too flexible to sand properly and just clog up the sandpaper and leave a rough surface.  A product needs to be reasonably hard to be able to sand cleanly and leave a smooth surface.  Also a flexible sealant will not have the structural integrity to hold pieces of timber such as the corner of a window together.  See last post at https://www.renovateforum.com/f84/wh...n-wood-113560/ . 
Sika may have a suitable product.  I plan to contact them and see if they have something suitable in their large range.

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## ifhaun

> I think this is the "Swedish filler" that a painter used on my house some years back.  It is a white material with a grainy structure

  The Super Filler is grey grainy stuff (but can be tooled smoothly). If the painter used white stuff, it might be another one of their fillers which I haven't tried.   

> Selleys technical department .. advised that they do not have a replacement for Liquid Nails Waterproof ... Selleys Pro Series Adhesive/Sealant may be worth a try

  I had a look at the Internet Archive Polyurethane Construction Adhesive at Selleys | Selleys Australia from 2015 which shows both Pro Series Adhesive/Sealant and Liquid Nails Waterproof so the Pro Series one appears not to be Liquid Nails Waterproof rebadged. 
Good luck with your search.

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## GraderL

Sika technical department has recommended Sikaflex 11FC elastic joint sealant and multipurpose adhesive for window repair.  Sika products are excellent but my concern is that it may be too flexible for this application. 
Has anyone had experience with 11FC?  Does it sand satisfactorily so you can get a smooth surface for painting? 
Appreciate any feedback on experience with Sikaflex 11FC and suitability for repairing windows.

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## Marc

The wood boat guys like to use this. I never had the need for it.  Welcome  http://secure.portline.com/rotdoctor/epoxy/AppGuide.pdf

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## TheHammer

The only product that makes permanent repairs to rotted and missing wood is epoxy resin. Builders bog is polyester resin. It does not stick to wood very well. It is a really bad adhesive. Its good for filling screw holes. 
You can purchase premixed epoxy filler or you can take liquid resin and stir in filler powder to make it into a putty. 
West System is the best known epoxy company in the world. Bote-Cote is an Aussie epoxy company. The typical way to repair a sill that can not be removed is done in three steps. Cut out as much rot as possible. Brush straight resin into the remaining timber(drilling small holes may be needed if its really deep) cut a new piece of timber. Apply thickened resin to the sill and use it to bond the new timber. Mix a thicker batch into a putty and fill in the remaining defects. Plane, sand or grind back the sill and paint it.

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## GraderL

Thanks TheHammer. 
Glad you agree with my experience that Builders Bog is useless for window repair.
It looks like epoxy resin is the best way to go.

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## Oldsaltoz

You can also use an epoxy based glue like Araldite by adding a little bit of filler to stiffen the mix if required. Talcum powder will work just fine.
This avoids the critical measuring and mixing process for epoxy applications. 
Note: Epoxy-based materials do not like direct sunlight and may turn a brownish yellow. A lick of paint will prevent this. 
Good luck and fair winds.  :Smilie:

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## TheHammer

Builders bog is good for filling screw size holes or gouges in timber. Polyester resin does not stick to any house paint(primer or topcoat, oil or wb). You need to sand off the existing paint. Fill the holes with putty, leaving a little extra lump to sand scrape back. Then prime it with something like BIN or fast solvent oil primer. 
Builders bog is a cheap version of automotive filler. We choose to use the Motospray polyester lightweight body filler. It is simply 10x better in every respect.

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## TheHammer

West system epoxy is not hard to use at all. The precise measuring is absurd. The easiest way is to use a container that is marked in ml. Add 1 part hardener and 5 parts resin. Stir it really well. They have calibrated pumps but they are unreliable at best. The accuracy of epoxy resin in the 20% range. You lose a wee bit of strength, but it will all cure. No loss of adhesion. I typically use kitchen measuring cups for decent size batches and small under 50ml measuring cups for small batches. 
The Bote-cote is 2:1. Anyone can measure that.

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## Oldsaltoz

If using and epoxy resin mix, make sure you sand it well after curing. Epoxy will stick very well to almost anything, but if left smooth your paint may peel after a short time. Also, note epoxy will suffer if exposed to sunlight so painting is critical. 
Good luck and fair winds.   :Smilie:

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## Marc

Epoxy is sensible to parts measuring but within reason. Critical strength like building a glider? Critical measuring. Making putty for a rotten window? best guess is ok. I also use cooking utensils to measure volumes of epoxy resin or two parts epoxy paint. Easy to dispose after without feeling guilty ...  :Smilie:

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## TheHammer

I specifically use the cooking ones from the cheap shop because they are made from polypropylene(PP). Pretty much no chemicals eat thru it. You can leave acetone in it forever. 
The epoxy cures and you can pop it out of the mixing container and reuse it.  
Yogurt cups are really good as well. Any plastic marked PP is the go. My favorite containers for painting are the Vaalia yogurt containers. They fit perfectly in your hand and can be washed out many times with wb paints. Likewise PP.

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## Marc

i don't know ... I would have second thoughts with containers marked PP ...  :Pee:

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