# Forum Home Renovation Cladding  Repairing small rotten ends to weatherboard joints

## roscored1000

Well brains trust the question has been stalled long enough, the carpenter who installed badly, not me, didnt paint  the ends of the weatherboards when they were installed about 10 years ago, here in melbourne. So of course there is a bit of rot starting in some of the end joints. I can either cut them out between 2 studs or cut the minimum out and use a product like builders bog. 
So is bog the right thing to use if I go down that road, any recommendations?
I have heard that bog shrinks and drops out and is a short term fix only? True/false 
So replace is better but more mucking around even in covid lockdown but is it necessary. thanks

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## droog

The timber will shrink and contract leading to the bog falling out. For rotted timber epoxy is the product to use but would be difficult to use for weatherboards.
Cut it out and replace, best to replace a longer length as just cutting to the next stud is going to look messy. The longer length you remove can be docked at the rotten end and used elsewhere for repair. 
If you go down the path of trying to use filler you will find out that replacing a section is *less* mucking around in the bigger picture.

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## roscored1000

thanks Droog I was afraid you would say that

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## gpkennedy

Now that we have taken the boards off the wall, prime the back of the boards!

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## johnc

What Droog said, of course undercoat every bit of cut timber.

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## droog

Once you get started and get a good routine for removing a single board you will see that it is not a hard job and much better than putting some filler in it that will fall out in 12 months.
Get yourself a narrow saw that will reach up under the board above, mark out where the centre of the studs are and lift the board above just enough to get the saw up to cut it.
Weatherboards should be nailed high enough up to miss the board below, often people don’t nail high enough. Once the board is cut if it is held by nails at the top just reef it out and trim the replacement so it can be fitted.
And yes paint everything, I suggest an oil based primer undercoat I believe they are better for exterior applications but others will have their own preferences.

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## phild01

I would putty up the joins as well, after priming.

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## joynz

You can use Earls wood hardener if you don’t want to remove the rotten wood. 
I’m using some on my window frames now.  Means you don’t have to remove the wood.  
On painted wood, you just drill small holes angled downwards in the wood (not all the way through. Then inject the hardner with a syringe (it’s $25 for 250ml -  so this is least wasteful compared to spraying or brushing). 
Once it dries, fill the holes and paint.  Works really well with window frames.  
I have also successfully used hardener and bog on rotten window frames in the past.  After 12 or so years,  I got a bit of cracking where the bog met the wood (I had removed the rotten wood and filled with bog before I found out about the wood hardener option. I had to shape entire profiles out of bog where they had been half eaten away...) 
These days I would try Earls external flexible filler - at least on the top surface - instead of or on top of the bog.  Though I don’t know if is as easy to carve into shape as bog.  
With rotten, weatherboards, however, I would be tempted to just replace the rotten section.

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## Compleat Amateu

As a rotten-wood-fixer I find Boat Cote epoxy products much better than Earls and much more flexible (microballoons and all that) ...... but I reckon replacement of board sections would be easier!

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