bondo and mdf

[zapdafish]

I have some holes in mdf I want to cover up and then paint. Is Bondo a good idea for that? I've read that wood fillers could shrink and cause problems. Never used bodo before so thought I'd double check and see if there are any other suggestions.

 

[walnutjerry]

Steve-----------I think that is an excellent choice. We used bondo on doors etc. when I worked for the millwork company. It does a real good job.

Jerry

 

[zapdafish]

cool, thnx

 

[Alan in Little Washington]

Bondo is made with polyester resin which does shrink a bit when it cures, but it has a lot of solids in it so should be fine. I've used it to repair painted projects, carpenter bee holes in my soffits, and holes in my Hardi plank siding.

 

[ErnieM]

Great stuff! I think my dentist fills cavities with it :rotflm:.
Ernie

 

[toolferone]

I picked up that tip at a cabinet shop I worked at years ago. I use it all the time on painted projects.

 

[zapdafish]

boy, gotta prepare enough for only 2-3 holes at a time with this stuff as it sets really fast once the hardener is added. It worked out great once I figured out how to use it. Hard to imagine but it generates even more dust than MDF does.

 

[ErnieM]

Use less hardener. Assuming you're using actual Bondo (other brands are different colors) the pinker the mix - the faster is hardens. A paler pink (less hardener) will give you more working time.

Ernie

 

[JimD]

Too much hardener works better than too little. You probably won't do it more than once.

Jim

 

[Dean Maiorano]

Just a note for all you Bondo fans - IF you ever use it in your house, make sure you vacuum up the dust adequately. Especially if using near carpets. The benzoyl peroxide in the hardener will bleach color from 'acid set dye' fibers, nylon carpets being one of them.

I used to perform all manner of construction repairs with Bondo but for MDF I preferred the two part epoxy putties. The main reasons were that it didn't shrink back (Bondo can leave a fine line around a repair), the epoxy hardening was more uniform (same general time frame each and every time, no gauging to see if I had too much or too little hardener), the epoxy is thicker so it will stay up on vertical surfaces, it shaves down nicely when in the 'gel' stage, sands better and its dust is less obnoxious (though that last one is more opinion than fact). I've used Bondo on a daily basis for a total of ten years and it was later in that period that I started moving towards epoxy putty.

 

[zapdafish]

I was able to see that the Bondo did shrink back slightly but I'm not to worried about it. After I covered everything with primer and sanded that smooth, I couldnt see the very slight indentations anymore. The can I got will last forever.

 

[Gofor]

Bondo is good and inexpensive. Works well in a lot of applications. However, If it really needs to last, use Marine Tex. You can also tap and thread it if necessary. Comes in 2 basic colors: White and black (altho the black is actually more of a dark gray).

Go

 

[Don Alexander]

just replace the mdf with bondo it will last longer :gar-La;:gar-La;