3M Bondo Spot Putty 2 and 1 Part

I recently used both Bondo Professional Spot Putty (2 part) and the 1 part spot putty.

First, I'll comment on the 2 part professional putty.

It comes on to parts, a large tube of resin filler and a small tube of red cream hardener. It mixes easily per the supplied instructions. It applies easily and is easily worked until the end of its working time. For me, it's stated working time of 5 minutes is somewhat generous. I guess the little bit of mixing eats into the working time, so work quickly. It quickly becomes cakey. It's pink after mixed and dries a light pink. When not applied heavily, it is EASILY sanded with 220 grit sandpaper after 25 minutes. It doesn't seem to clog sandpaper too much. It takes paint very well. Over all I liked it, but the working time is short.

The 1 part Bondo spot putty is about the color of dried blood. It has a working time of about 7 to 10 minutes. After it is squeezed out of the tube, it quickly develops a skin, but it doesn't really effect application and easily mixes back into itself. It, too, is easily worked and sanded. It takes a bit longer to dry than the 2 part, about 30 minutes. Heavy spots may still be soft. I found the 1 part putty to clog sandpaper much more quickly than the 2 part. Readily accepts paint. Its lengthened working time and 1 part system makes it quick and easy to use.

Edit: They both off-gas quite a bit. Either do it outside or wear a mask in a WELL ventilated room. They each produce a fair amount of dust when sanding; wet sanding is advantageous for keeping the sandpaper clean and preventing sanding dust. I didn't notice any adhesion or shrinkage issues, sanding soon after the allotted time. I did, however, have to go back an refill some low spots after sanding.

They are both good products and I would use them again.

I've used it a few times and it works well for filling cracks a small spaces.
It makes a big mess when sanding, best to wet sand with the right sand paper.



JD

I found the Pro G&SP harder to sand, but it adhered better than the 1-part. Working time is BRIEF and it stinks like hell for a couple of days afterward. Have your application tool ready and rehearse how you will scoop up and spread it ahead of time so that you don't waste precious seconds when it is time to do it for real. Only apply it where you have PLENTY of ventilation!

JDcluster said:

I've used it a few times and it works well for filling cracks a small spaces.
It makes a big mess when sanding, best to wet sand with the right sand paper.



JD

Click to expand...

I have not found a lightweight filler yet that doesn't generate vast clouds of dust when it is sanded. I comes with the territory, I guess. I sand my fillers outdoors whenever possible and wear a dust mask when I remember to.

You can thin the 1-Part down with a little acetone. With a bit of thinning, you can apply it like paint with a small brush.

I let both versions of BG&SP dry overnight before sanding them. I want them to be completely dry through and through so that I don't have to worry about adhesion or shrinkage.

I use bond spot putty for small areas and touchups. For large projects where weight is not desired and easy of sanding is, SuperFil from aircraft spruce is a must have.....try it and you'll never go back....