slowing drying times of body filler
I am using Bondo 261 (lightweight filler) and 907 (glazing putty) in reshaping an existing fiberglass hood scoop (adding a centerline ridge). Is there anything I can add to this material to slow the drying times - extend the working time?
Or is there a better product to use for this application in Gulf Coast summer?
One thing I've done to slow the drying time of any catalyzed body filler is to add maybe about 5-10% by volume of fiberglass resin. A or B, either will work. Just a little bit. It is the base material in all body fillers, so the catalyst will cause it to harden. This makes the filler very smooth, it will thin the material, and it tends to flow a bit, but if you don't use too much, it will allow you to work it a bit longer. However, there are some things to pay attention to. One issue is, when it goes off and hardens, it kicks off very quickly! Be ready! When it starts to set, stop messing with it, cuz if you don't, you'll end up with a mess of pinholes. It can also eat up sandpaper cuz it will clog the first sheet, so, use an older, worn piece of 40G to "break it open" and take the skin off it, then go after it with fresh paper on a block. I used it in all my filler for 25+ years, and when you get used to it, you'll be able to use it to your advantage in laying on the mud nice and smooth. You'll spend less time sanding, and use less material. Also, I never liked the "lightweight" body fillers. Too many issues with chalky sanding, pin holes, adhesion to bare metal issues etc. Just my 2 cents worth-good luck...
PS-just a general body filler tip-use flat black spray paint as a guide coat-sand it to the general shape you're after, then blow it off and mist on a guide coat. Hardly anybody does this, but it will help you sand your filler smooth, find any pin holes, and get all those 40 grit sand scratches out...I know, long winded, but I get goin' and, well...
Hoof