The Handyguys answer a question about using bondo on rotted wood and they discuss the different varieties of ladders.
The Handyguys Brian & Paul answer a question about using Bondo for wood repairs submitted by Moe.
My house was built in the late 70’s and lately I’ve noticed that some of the windowsills (exterior) have patches of rot. Replacing a windowsill seems like it might be beyond my expertise so I’m wondering about removing the rot and filling it with something. I’m told Bondo is a bad idea. Do you have any recommendations on what to use and how to tackle a job like this?”
Thanks for contacting us Moe. This is a great question.
The Handyguys start off discussion what Bondo is and how it can be used for wood repair applications.
Below are excerpts of The Handyguys email responses to Moe. More details are available in the podcast.
My first inclination is to replace the rotted wood. Weather or not you need to do this depends on the extent of the damage. Feel free to email us a few pictures and we can give you a better assessment. In my opinion replacing the wood is actually easier and looks significantly better when done. I sometimes have trouble making a patch disappear after I paint. If replacing the wood is definitely out then you have a few general steps.
1) Remove ALL loose wood, rotted wood, dust and debris. If you do not get out the rot it may continue deeper. A tool like a Dremel can help with this along with scrapers, utility knives and so forth.
2) Harden remaining fibers
There are products made for this such as
Or, if you had a ready supply of Cyanoacrylate (super glue) you could use that to harden the fibers (the liquid type, not the gel)
3) Fill with exterior grade wood filler such as
4) Sand smooth
5) Prime and paint
The hard part is when you have edge details or unusual shapes.
I have never used Bondo but I do not see why your couldn’t as long as you went through getting the old rot out and hardening the fibers first.
And Paul’s 2cents
Just to piggy back on what Brian already said. I have used bondo on exterior wood applications and I like it. I used the version that is sold in the paint section of the big box stores for just this application. I think it is the same as the auto version.
I have used Bondo on a rotted porch post. I cleaned out as much rot as possible and applied the Bondo. It hardens fast so you have to get used to it. In my opinion Bondo works better for exterior applications then most other wood fillers for this purpose.
My porch posts have held up great. Make sure you prime and paint after it hardens. You can do this same day I believe because it hardens so fast.
Here is a link to Bondo for wood. (Sorry, its not available in our store)
The Handyguys then go on to speculate that Moe may need to work from a ladder and realize that they didn’t include ladders in their home toolkit show. This evolves into a discussion about various types of ladders.
Types of ladders discussed
Typical A frames in fiberglass, wood and aluminum. Paul likes the ones with fancy attachments.
Extension ladder pros and cons in fiberglass, aluminum and wood are discussed.
Brian likes the Little giant type
Paul highly recommends a ladder stabilizer with any extension ladder.