View Full Version : body filler aggravation

08-20-2008, 09:39 AM
I searched the forum but didn't find a solution for this, only several mentions of it. Seems no matter what brand of body filler I use and how much hardner, the filler has a gummy surface after it sets up that clogs sandpaper. I haven't heard anyone say if there is a way to get rid of this coating. Any suggestions?

08-20-2008, 09:59 AM
Gummy usually means not enough hardener, poor mixing, or wrong hardener.You should have to work pretty fast to spread the putty before it sets up, maybe as little as a minute or so.

"I'm a great believer in luck and I find the harder I work, the more I have of it."
Thomas Jefferson

08-20-2008, 10:03 AM
use a "surform" (cheese grater) file to do rough shaping, this will knock the surface down and then switch to sandpaper


55 Commander Starlight

08-20-2008, 01:20 PM
What JDP said, although it's hard to have to little initiator, more like a mixing problem. I'm currently finishing my 54 for painting and have switched to Evercoat Gold Extreme filler upon the advice of a couple of pro body men and am not having the problem you describe. It's about 2X the price of Bondo etc. but works 4X better.

08-20-2008, 01:31 PM
I'm using the hardner that came with the body filler and it usually sets up in about 3 - 5 minutes depending on the temp. Two different brands produce the same result. Maybe I'll try sweetolbob's Evercoat filler.

Warren Webb
08-20-2008, 01:36 PM
I have used a filler called "RAGE: that performs very well. Depending on the color (or for our commonwealth friends, "colour") the filler when mixed properly should be "about half way" in tint from what is in the tube & a very pale mix. I would suggest you do a few small applications to find the right mix to suit your needs. I would also recommend when first applying, spread a very thin layer with firm pressure, then follow right away with another layer more to the desired thickness you need. I would stay away from the cheap brands usually found at your local FLAPS & buy from a body shop jobber such as Finishmaster. They are a nationwide chain, but there are many mom & pop jobbers too that will get you what you need. Check your yellow pages under "auto body supply". Hope this helps!

60 Lark convertible
61 Champ
62 Daytona convertible
63 G.T. R-2,4 speed
63 Avanti (2)
66 Daytona Sport Sedan

08-20-2008, 02:08 PM
My Bad, I should have checked the can. I'm using Evercoat Rage Gold. A mind is a terrible thing to waste. If the setup is 3-5 minutes, you have plenty of initiator.

08-20-2008, 02:16 PM
My experience is any filler I have used left a slighty gummy surface when it was cured. The cheese grater (or some body files) were needed to get the top layer off and then sanding blocks work OK as its not gummy underneath a thin skin.

The thing to [u]never</u> do is mix filler brand A with hardener brand B. I ran out of hardener once and used some from a different brand I had and it only partially set up. What a sticky mess! Basically gummy all the way through. Had to use wood chisels to scrape it off the fender, then a wire wheel (which clogged up) and finally thinner to get it all off the metal so I could start over. [xx(]:(:(

Jeff in ND
'53 Champion Hardtop

08-20-2008, 09:46 PM
Agree with N8 and Jeff_H, that the cheese-grater file is the way to go. Get a couple of the long straight ones with a slightly convex cutting surface. Don't bother with a handle; the pros don't. Mix and apply the filler, and as soon as it becomes solid but BEFORE it fully hardens, sculpt it roughly into shape with the cheese grater.

This is not only cheaper than wasting sheet after sheet of sandpaper; it's easier and faster, too. Using the cheese grater without a handle allows you to bend it to conform with the shape of the panel on which you are working, enabling you to cut the filler down very close to the final profile, eliminating most of the sanding.

Gord Richmond, within Weasel range of the Alberta Badlands

08-20-2008, 11:39 PM
I think you need to be careful using a grater on partially cured filler, if you hit it a little early it will lift the edges of the filler and screw up adhesion. Makes a worse mess than the clogged sandpaper, bet you don't need to ask me how I know. My opinion of the problem is that the inexpensive fillers have a higher level of carrier material and low molecular weight tails in both the filler and the initiator. This results in migration of the more flowable material to the surface plasticizing the material. My guess is that is why the premium products do not have this problem. You-all gits what you pay for.

08-21-2008, 02:54 AM
You might want to try 3M Drywall Screens. Very flexible, almost
clog proof, and very long lasting. Plus you can get it in fine -
coarse at any big box home improvement store

08-21-2008, 02:37 PM
Wash it down with lacquer thinner before you sand it. Or spray primer on it before it cures.