What is the gray filler that I've seen used as knot filler, like in alder plywood? Looks like bondo, I don't think it's epoxy, turns black with poly.
What is the gray filler that I've seen used as knot filler, like in alder plywood? Looks like bondo, I don't think it's epoxy, turns black with poly.
Yeah, sounds like Bondo. Made to fill and smooth crumpled and dinged metal . Then brave wood workers used it to replace poorly made
too small knots. Good for lots of stuff. But never make it a face cream gift to your wife !!
20220730_102759.jpg
This is a pic of the filler.
If it's not Bondo brand stuff, it looks to be remarkably similar material. It's good for "non beauty" filling because it cures extremely fast so it can be surfaced with very little wait.
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The most expensive tool is the one you buy "cheaply" and often...
I have used Bondo on many wood projects but I have always painted it. I have never thought of trying Bondo under a clear finish.
Looks a lot like JB Weld
There are many types of "body filler", including some flexible ones to use on plastic vehicle parts like bumper covers. All the flexible ones I've dealt with are gray like that.
Just search "body filler" on Amazon, and you will see what there is to choose from. Some are much finer, and easier to smooth over than Bondo brand, like some made by 3M.
If it's what comes in some plywood, I expect it's whatever is cheapest.
There is also "glazing putty" that has nothing to do with window glazing putty for smoothing over small imfections in body filler after you do the best you can with it. Glazing putty comes in tubes like toothpaste, and what I've ever used is red. It's one part and no mixing like body filler.
edited to add: The flexible ones are epoxy based, whereas all the others are polyester resin.
Last edited by Tom M King; 07-31-2022 at 9:18 AM.
If I remember right, my Bondo is pink. Of course the can is over 30 years old (still good). Maybe they put in a different color for various blends. I know I have seen Bondo products made for wood.
30 years ago I rebuilt some window ledges in a rental that a pit bull had eaten. Still there, and some of the patches are at least an inch thick or more.
OOOH, gotta tell this one: My first introduction to Bondo was about 1961, when a neighbor slammed the door of his 52 Plymouth, and the whole face of the door fell off. Someone had repaired a large 3" or so deep dent which went from edge to edge on the door, by simply filling it with a huge slug of Bondo, must have been well over a gallon of the stuff. They made no effort to pull the dent out at all.
Asked the owner what that stuff on the ground was, and that was my intro to Bondo.
Last edited by Rick Potter; 08-05-2022 at 2:48 PM.
Rick Potter
DIY journeyman,
FWW wannabe.
AKA Village Idiot.