sanding body filler

[clstolten]

what is the quickest way to knock bondo down so that it can be finish sanded. I am using 80 grit on a block and getting the job done, but it is a slow process. If I put the 80 grit on an air powered block it works pretty quickly but my compressor runs alot, and I am getting worried about what my electric bill will be. Should I try 36 or 40 grit by hand? What is the proper tool for the job? Thanks.

 

[zeroz400]

Im not very knowledgable on the whole body work thing but here's what i've been doing. After the filler starts setting a little bit i use the cheese grater to knock off the big edges. Then i follow with the longboard using some 36grit paper, where i could i used the air file which cut the time down alot. After the first coat of primer i was using a filler called "icing", it was thinner then regular filler. I sanded that down with the longboard using 180grit paper.

You said finish sand but you prolly need to get a coat of primer on their cuz there will prolly be more imperfections that you'll have to fill and sand. That should get you in the ballpark.

Ryoken will prolly chime in soon and offer better advice.

 

[ryoken]

Zak pretty much covered it....

I'll just go thru my procedures....

always make sure you got a good rough grind and don't be skimpy, go well past the dent. you want bare metal between your mud and old paint.. apply mud...

Cheesegrate to knock it down and get an initial cut... once the bondo flashes off and begins to stiffen up, drag the cheesegrater corner over the mud, making a line or "score" to verify when it's hard enough to cut.. some guys skip this and go right to 36.. up to you, how big the area is, wastes your sandpaper a little more, etc...

Longboard or block with 36... get about 90% done with the 36.. crosscut when possible to check for low spots..

finish with 80... blow off... check low spots.... refill and repeat as nescesary... featheredge any exposed paint areas with 180 to 220..

prime.... throw 2 or 3 coats of some good hi-build on it...

once flashed off, use a squeegie to skim coat with a glazing putty to fill any sandscratched, pinholes, etc... wetsand with 180 to 220.... reprime.... wetsand with 320 to 600 (depending on topcoat) and paint...

 

[clstolten]

Thanks for the help guys. I will pick up some 36 grit.

 

[chevyin]

Another advantage of using a cheese grater file is that it removes the "skin" from the filler. By doing this you greatly increase the life of your paper.