Body Filler

[Silverback]

I’m curious… what do you guys like for what application (normal body filler, glazing, repairs/glass reinforced) and why? Anything that you’ve had surprisingly good results with? On the flip side, is there something out there that you absolutely hate/have had bad results with?

I’m more of an amateur hack, but I’ve done some pretty decent body work before and have never had problems even with the run of the mill bondo and bondo glass (well, at least after I figured out that they were UV sensitive…), but a friend of mine just turned me onto Evercoat MetalGlaze for small/quick repairs, and now I wonder how I ever got along without the stuff. It’s starting to look like I’m going to be hammering a bit of metal to get my latest project car to where I want it to be so I’m wondering if there are other products that I should try to make my life a bit easier, but because I plan on keeping this one a long time I would like to avoid some of the learning curve of experimenting with new stuff to figure out what works nicely and what doesn’t.

[GRIFFIN]

I've always liked evercoat products, Just get a premium lightweight filler. As far as glazes and finish fillers, I'll share a little trick. Buy some SMC resin, it uses the same cream hardner as the fillers. On your finish coat of filler, add a little bit of resin into your mix. It makes it smoother and you will not have to worry about pinholes, I usually finish it off with 180 grit or maybe even 220.
Those expensive finish puttys have the same compounds as the regular body fillers, they just have more resin. You can tweak your mix with that SMC resin to get it to match your preference. It will not shrink on you either. I have used it on insanely high dollar customs and never a problem.

[Silverback]

The same friend was recommending trying their z-grip, though after reading through the descriptions I wonder if it’s jus the extra corrosion protection of that and the metal glaze that he’s hooked on (and I wonder if it makes a real difference).

Sounds like you’re as happy with their cheap stuff as he is with the ZGrip, and no one is overly excited about their “premium” stuff, rage/rage gold/rage extreme… not sure why really.

As far as adding resin to the filler… I’ve done that for years for cleaning up one off fiberglass parts… I’m guessing it’s not an original idea, just using the bondo products for each, when I had a rough spot on a custom fiberglass part in the surface finish, I would take some bondo, and some bondo glass resin, mix them up and sort of float it out, the stuff would be buttery smooth.

Is there something special with polyester glaze that allows you to apply it to paint/primer…? I was under the impression that you shouldn’t use normal filler except when sticking it to steel or to itself…

[GRIFFIN]

You should not use regular fiberglass resin to mix in, it uses a different hardener (liquid). SMC uses the same cream hardener as the fillers. Especially in fiberglass type fillers or the MetalGlaze.

As far as the "premium" fillers like Rage, I've used alot of it. That is what most shops around here use. It works well but I still always add a little resin on finish coats. The main difference in the premium fillers is the amount of resin in it. Resin is more expensive than the talc, so they use less of it in the cheaper stuff. Buy a quart of it and it will last you a long time.

No, there is nothing special for going over the top of paint in the polyester glazing putty as apposed to something like the Rage filler. As a matter of fact, most paint companys these days recommend putting your plastic over a good epoxy primer. I do not like to leave anything in bare metal any longer than is necessary.

Do you use a good epoxy type primer? If so, put a coat of that on first then do your finish work.

[Keith McCoy]

Silverback we prime all of our bare metal that needs filler with DP epoxy primer(PPG) it has rust inhibitors etc,in it and then a K36 primer over that,the DP has to be primed within 24 hrs. You dont want to put your filler over bare metal the filler will heat up the metal and over a period of time the metal will start rusting resulting in bubbles chipping paint etc. Scuff your primer with 80 grit and apply your filler. It sounds like you know what is going on with the many kinds of filler that is out there, the cheap stuff will get pinholes in it and thats bad it just makes more work for you.We prefer the Evercoat line,use the glazing puddy for thin layers its easy to apply and sand,many times we will smear a complete fender with the glazing puddy and sand it,you will use less primer by doing it this way,and now days primer is cashy. hope this helps. McCoys Auto Creations

[Silverback]

Huh… both of you are agreeing and you’ve got me slightly confused now…

Wouldn’t normally you put down some etching primer right on the metal and then use the DP later on, after bodywork (maybe I’m a little old school there, that’s what I did on my last major job in the early 90’s, since I stripped large parts of the car to the bare metal)? I was under the impression that DP epoxy was a good primer/sealer (also the reason DP 90 was recommended for people that wanted to run their cars around in primer, since it was waterproof and pretty much sealed up your body work).

Putting it over a layer of primer also seems somewhat contrary to evercoat’s advertising, where everything besides their base filler seems to come with additives specifically for corrosion protection and adhesion to galvanizing, aluminum and other rust preventative coatings.

Keith, you hit the nail on the head with the glaze… I’ve never used anything thinner then plain old body filler on a project before, but in this case I’m hoping to give the whole repair area a very thin skim and avoid using a primer/surfacer and as much primer as I would otherwise.

[Silverback]

I guess since you’re all agreeing about at least a brand (as well as the people that I’ve talked to in person), maybe I should give you a better idea of what I’m doing and see what you would suggest.

With an exception of a problem on the hood that I haven’t decided on a direction with (I’ll probably start a separate thread), the new project is pretty much straight and rust free except for 2 bits of body work that I don’t like how they were done, and were left in bare bondo so I plan on totally removing it and starting over. The second thing is that I will probably drive it on and off during the process and in no way can I leave it disassembled/inside for an extended period, I just don’t have the garage space and way too many projects.

So the current pan is to just fix the 2 sections and put some color over them (I doubt that I’ll even try blend it into the rest of the body, since the rest of the paint is old/neglected/faded), and then sometime in the future after it’s gone through a drivetrain swap and had a proper cage installed I’ll sand it all down, fix any little door dings… and paint the whole thing and make it pretty. Like I said, for now though, I just don’t want it to look like a beater from 50’ away. I want to get rid of the big bondo patches, but I also want to make the repairs good enough that later on I don’t need to strip them and re-do them again..

That being said, it’s not like I’m going to spend days on each step and need to protect the bare metal in between steps, the only reason that any of the repairs might take more then a day _total_ is if I run into some hassle with materials or something. Both repair areas are probably around 2sq feet probably including blending the body work into the existing body

That being the case, my plan was something like:
- take off the existing bondo
- do any necessary metal work
- wipe down with metal pep
- body filler to get what I can’t get out with a hammer/dolly, sand to somewhere between 180-320 grit depending on how close it’s coming out
- skim coat the whole deal with something like the metal glaze, sand out to 400, maybe 600 (wet??? I’ve never had the guts to wet sand bodywork because I’m afraid of water soaking into the filler, but I know how much better it works and I’ve been seeing a lot of recommendations to do that lately with the finer grits)
- hit it with primer/sealer, if I’m lucky I can avoid any further body work at this point
- BC/CC

Now if I was doing the whole car at once I’d probably spray it down with primer right after stripping it to protect things and it would make it easier to find things like door dings…, but I’m not doing a whole car and I shouldn’t have any bare metal long enough to need to protect it.

So does this make sense? Would you do it differently?

[68 nova 10.5]

I guess since you’re all agreeing about at least a brand (as well as the people that I’ve talked to in person), maybe I should give you a better idea of what I’m doing and see what you would suggest.

With an exception of a problem on the hood that I haven’t decided on a direction with (I’ll probably start a separate thread), the new project is pretty much straight and rust free except for 2 bits of body work that I don’t like how they were done, and were left in bare bondo so I plan on totally removing it and starting over. The second thing is that I will probably drive it on and off during the process and in no way can I leave it disassembled/inside for an extended period, I just don’t have the garage space and way too many projects.

So the current pan is to just fix the 2 sections and put some color over them (I doubt that I’ll even try blend it into the rest of the body, since the rest of the paint is old/neglected/faded), and then sometime in the future after it’s gone through a drivetrain swap and had a proper cage installed I’ll sand it all down, fix any little door dings… and paint the whole thing and make it pretty. Like I said, for now though, I just don’t want it to look like a beater from 50’ away. I want to get rid of the big bondo patches, but I also want to make the repairs good enough that later on I don’t need to strip them and re-do them again..

That being said, it’s not like I’m going to spend days on each step and need to protect the bare metal in between steps, the only reason that any of the repairs might take more then a day _total_ is if I run into some hassle with materials or something. Both repair areas are probably around 2sq feet probably including blending the body work into the existing body

That being the case, my plan was something like:
- take off the existing bondo
- do any necessary metal work
- wipe down with metal pep
- body filler to get what I can’t get out with a hammer/dolly, sand to somewhere between 180-320 grit depending on how close it’s coming out
- skim coat the whole deal with something like the metal glaze, sand out to 400, maybe 600 (wet??? I’ve never had the guts to wet sand bodywork because I’m afraid of water soaking into the filler, but I know how much better it works and I’ve been seeing a lot of recommendations to do that lately with the finer grits)
- hit it with primer/sealer, if I’m lucky I can avoid any further body work at this point
- BC/CC

Now if I was doing the whole car at once I’d probably spray it down with primer right after stripping it to protect things and it would make it easier to find things like door dings…, but I’m not doing a whole car and I shouldn’t have any bare metal long enough to need to protect it.

So does this make sense? Would you do it differently?I like to finish body filler in #80 then glaze then back to #80 then #120 then #220 2 coats primer surfacer depending on the finish of the surfacer start with #180 then #220 then #320 I absoulutly hate wet sanding its messy takes too long etc all the previous listed grits come in file board rolls by the time youre done with the glaze you already have it straight so after that all your doing is removing the previous grit scratchs if youre using a sealer after this a finish of #320 is fine if not go over it with #400 (wet if you like) also use a guide coat between grits

[Keith McCoy]

Silverback just give Pops a call(David) for a one on one Sundays are fine also 309-343-9815. thanks Keith McCoy

[GRIFFIN]

Silverback,
I would not in any way recommend wet sanding the raw body filler, especially if you do not put a epoxy down first. The filler is porous and will absorb water, it will not actually hurt the filler (it will dry) but it will put moisture against your bare metal, causing corrosion and chalking.

For what you are wanting to do, you can get away without putting an epoxy down first, since you are doing small and quick repairs. Just dry sand them in steps down to a 320 grit finish and apply 2 coats of a good primer filler. I've done it that way for years. Use the glazing (or add more resin) on your finish coat and get your body work straight and all you will need is the 2 coats of primer.

I hope this helps answer your question.

[Silverback]

Yep… that about does it, and pretty much agrees with what I figured I’d do. Like I said, I don’t have the guts to wet sand because of the water absorption issues anyway.

Keith, thanks for the offer, but I pretty much don’t have time to pay attention to the boards except during the middle of the night so I’d never remember unless I ran into an “emergency.” And at this point I know that what I’ve listed will hold up for at least a few years, probably longer based on my previous experience, so it’s unlikely I run into an emergency.

[Silverback]

Actually, while I have your attention why don’t I continue this a little further, maybe I’ll learn a little and someone else might benefit from it in the future… I have a couple more questions:

What’s the deal with lightweight vs heavyweight polyester fillers? Seems like most are lightweight, and I’ve never even heard of anyone suggesting using the heavyweight fillers, what are they used for?

Secondly, turns out the bondo on one of the fenders is a fairly thin coat, but the monkey that put it on use it to cover half a million holes that they left with an old screw type slide hammer (no stinking clue why someone would use one there, since the back side of the panel is very easily accessible and hammer/dolly work would have been MUCH easier to do).

The friend of mine that does this day in and day out (and mind you, does some killer work) is strongly recommending that “since it’s not a show car, save yourself the time and effort and clean off the bondo and just wipe it down with some short strand ‘glass filler and get on with your life.” Where my instinct is to pull out the welder and weld all the holes shut.

At first I was surprised that he would recommend something that seamed so half assed to me, but then he explained “Unless you grind the front and the back of the welds down someone digging behind the trim panels will still be able to tell that it’s been repaired, it really doesn’t matter on this car, and if you do sand the back of the panel down you’ll just be removing the factory rust coatings that are still perfectly intact on the back of the panel, and with the number of little holes they left in a small space you’ll be lucky if you don’t warp the hell out of that part anyway.”

Thoughts? It’s an area much less then a foot square, so it’s not like I have a big messed up section to deal with anyway

[GRIFFIN]

For what it sounds like you are wanting to accomplish, your friend is giving you good advice. That will still hold up for a long time and will be alot less headache. Just be sure to spray the back side of the panel after you are done with some etch type primer or epoxy, then probably some undercoating.

As far as the lightweight body fillers vs heavyweight, my understanding is the lightweight produces less pinholes (supposed to anyway), but is not designed to be applied very thick.

[BruceO]

If the holes arent that big you can just use filler without the strands.i never was big on the stranded stuff..hard to get a good mix and doesnt lay out smooth.only used it on bigger holes.as for as Bondo (filler) i like Evercoat Rage filler,sands easy and non staining.just spray something behind it if youre worried about rust from the holes after youre done.

[Silverback]

They’re just screw holes from a puller, probably less then 1/8” in diameter…

Been messing with other things and kind of looking at it… I’m actually debating welding them and grinding it just to play with metal shrinking. Always wanted to make a shrinking disk and try that out…

[totalchaos]

like the evercoat rage products also.

[totalchaos]

They’re just screw holes from a puller, probably less then 1/8” in diameter…

Been messing with other things and kind of looking at it… I’m actually debating welding them and grinding it just to play with metal shrinking. Always wanted to make a shrinking disk and try that out…
i would weld the holes up no reason to leave them for rust issues later down the road

[Silverback]

Heh, this has been awhile… fwiw, I just welded the holes and did a lot of metal work, but then as I messed with the car more I found more and more body filler and more and more holes (and less and less time), and finally totally replaced a door after I couldn’t bring myself to actually grind off the big line of bondo considering what I found under the rest, so the thing has pretty much stayed apart in the garage as a project and is everything is getting welded up.

After that is done and the inner wheel wells modified enough to fit the new tires on it, I’ll probably roll it out, wash it, hit it with some metal prep (deal with any light surface rust that I might have gotten from the metal shrinking process), epoxy primer it, shoot everything that isn’t dark red or black with some cheap flat black that I have and let it roll like that for a while till I get the rest (mosty mechanicals) done like I want them.

[Bubstr]

The key to shrinking metal is to heat a dime sized red spot, hold your backing dolly very loose to a little bit away and as you hit the red spot work from outside ring going in only hitting it hard enough to move metal, then a cold rag quench. Repeat if necessary. Your really trying to push excess metal to the center of the hot spot. Never try o shrink a concave area or close to a body line that puts the spot below the panel average. It just don't work. Cold work that area and if necessary pick the whole area up with light pick hammer.

Yes I'm old school, first shop I worked in didn't allow filler and if you used more than a stick of lead you got the evil eye from the boss.