I recently read an article touting the multiple uses of automotive bondo. One way in which its use was advocated was as a wood filler. I have some rot on a wooden column and a small patch on hardboard siding that I was thinking about using bondo to fill. I have now read a letter response to the article that says bondo is not appropriate for use on wood.
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Any experiences, thoughts, etc. Thanks in advance.
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Replies
I use bondo (the household stuff sold at HD, but I think it's the same as the automotive) on wood pretty often. It says that it's intended for use on wood on the package, and it's never given me any trouble, as long as the underlying surface is clean and solid.
zak
"so it goes"
I use it all the time and hgave never seen a failure.
Another proiduct specificly formulated for wood is made by Minwax. I t is a two part filler that is used the same way as bondo.
Minwax also has another product you may need for thjat column. Minwax wood hardener will penetrate The loose wood fibres near the edges of the rot area will not hold any patch material until you firm them up with this consolidator. IO drys in less than an hour, then you go to work with the filler
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There is a review of a new line from Bondo especially for homes on page 85 of the July/August 2006 Old HOuse Journal. This is the very short review, the type that is almost an ad.
Anyway, there are four kits for repairs around the house, for metal, wood, fiberglass, and all purpose.
I have heard of lots of people using the old bondo on wood. A few have noticed seperation when using it outside.
Personally, I stick to Abatron. It is designed for wood and tested for exterior usage. Sure, maybe Bondo is fine. But I know Abatron is.
I've used the Minwax version of bondo to correct some router mistakes on new windows. The filler is excellent for use on good sound wood. For rot repairs, you want to use the thin stuff that soaks in -- what Piffin said.
-- J.S.
Have been using Bondo for years. It's ok with interior woods. I like to paint on Minwax's 'Wood Hardener' before I apply the bondo however. You have to have a good bond because wood moves and the the bond will break. It also depends on the stability and the type of wood. As a fill for cabinetry that is being primed it really is great.
I won't use it on exterior anymore. Wood moves too much and Bondo does not move with the wood. It's too hard. Then what happens is water gets in between the wood and Bondo and you are finished.
Products like the West System, and WoodEpox are much better for the outside. They were developed to be used on wood unlike Bondo.
I always keep a can of Bondo in the truck.
Thanks for the fast responses.
Bondo is great for wood. It would be interesting to hear why the letter writer claims it doesn't work well for wood.
For an exterior filler it's the first thing I'd reach for, other than another company's version that is more expensive but shrinks less. Can't remember the name since the economy of buying bondo by the gallon is another great aspect of the product.
The Minwax "high performance filler" is made by bondo.
The Bondo made for home repairs is a slightly different color with a white hardener, but otherwise doesn't appear any different from the automotive stuff.
I've used it extensively with interior applications to fill plywood subfloor knot and fastener holes prior to painting (we're waiting a few years before paying for tile/wood/carpet finishes); and with exterior applications to fill plywood knots and delaminations prior to fiberglassing 900 sq. ft. of deck surface. I've probably used 10 gallons of filler in this house alone; lots for the deck because it endured a year of weather exposure which caused lots of delamination, cracks, and popped knots. I've got no complaints other than you have to mix small quantities and work fast.
On the other hand, if you mix it properly, you can start sanding 15 minutes after you apply it if you get the hardener/resin ratio right. However, if you mix it too 'cold', you may have to wait a day or two for it to harden. You get good at this after a while.
Anyone who thinks it doesn't stick to wood is dead wrong.
It binds to the wood with great tenacity, sands easily, and generally ends up looking better than the wood around it.
I've got pictures to send if you like.
Scott.
Always remember those first immortal words that Adam said to Eve, “You’d better stand back, I don’t know how big this thing’s going to get.”
I've used the automotive stuff for years without any problem, as long as the substrate was solid and clean. If I'm concerned about adhesion, I start with a thin layer, firmly squished into every crevice and surface.
If the hole is of any size, I fill it in 2 or 3 steps, rather than trying to get it perfectly with one step. Since you can vary the hardening time by varying the amount of catalyst and/or using a heat gun, this isn't much of a slowdown. Also, Bondo is like concrete: it needs reinforcement if it's of any thickness. I use some combination of drive screws, nails, and wire for this.
Large holes is one of the advantages of Abatron. It actually cures better the more there is.