Filling pet scratches, etc (with Bondo) on painted wood door, then sanding out with 220 I am getting these “residue blobs” on both the sandpaper and the area being sanded. They scrape off, but I’d like to solve this. I was thinking it was due to heat build up. Is there a need to sand bondo wet?
Also a friend told me when he used to do car body work he used to wipe tne new fill with laquer thinner to remove a surface residue before sanding. Assuming that wouldn’t hurt the paint around the fill is this the thing to do?
Replies
Typically, you wipe with laquer thinner before you put the bondo in......no reason to get the residue off before you're gonna sand, cause you are just creating more by sanding. The blotches are typical with bondo. You can use some rougher grit paper first---get the surface fairly smooth, and then finish with your 220 grit (for wood). One automotive they typically will wetsand with 400 grit wet/dry, and then use fill primer and wet sand some more, down to about 800 grit----lots and lots of sanding. Wood is not so hard!
Not a pro, but every bondo job ive done (mostly trucks) took 3 coats, sand first with rotary 36 grit, second with 100 radom orbital, final as fine as you like (220 sufficient for my tastes) by hand.
Oh yeah, you get a lot less gumming of the paper if the bondo cures for 3 or 4 days before sanding - not a quick job.
Why not use Minwax two part epoxy wood filler. Sands like a dream and fills like a sexual object.
Be well filled
andyCThe secret of Zen in two words is, "Not always so"!
When we meet, we say, Namaste'..it means..
I honor the place in you where the entire universe resides,
I honor the place in you of love, of light, of truth, of peace.
I honor the place within you where if you are in that place in you
and I am in that place in me, there is only one of us.
One thing I thought of is to make sure you're using sterated (sp?) sandpaper--the stuff with the lubricant built in.
Bondo is a pretty heavy filler for small scratches. On body work you start to shape it as it sets up, not when it is still wet. Bondo also makes a glazing putty/spot filler that doesn't have to be mixed. It's a much finer filler and sands easily. My personal choice for wood is Famowood filler, which is not a bondo like product. Quite a bit will depend on what you are filling, how deep it is and what condition the surface is in before filling.
Durams makes a good wood putty---looks like pancakes flour, and fills great