Reinforcing Bondo

[California 72]

Understanding the fact that Bondo and other body filler makers are selling aluminum reinforced products, what are your thoughts?

Has anyone ever added other forms of reinforcing materials, other than fiberglass, to regular body fillers and if so, what?

I'm trying to figure a way around using fiberglass or fiberglass reinforced products given my history with them and the level of distress it causes. Seriously, I still feel "itchy" almost 50 years later, even at the mere thought of using them.
Possibly looking at iron filings but that would take away the antirust capabilities, could pose additional issues with being waterproof or just not mix in any way.
Also looked for stainless-steel powder, used in cold castings, as well so any thoughts/suggestions would be appreciated
One upside to an iron-based product is that it would be "magnetic" (maybe not the stainless steel but depends on the quality) and able to pass the magnet test.

 

[detritusmaximus]

Look to West System Marine Epoxy fillers. There are various types that add an enormous amount of strength to the epoxy. Might work in Bondo.

The upside of iron sounds....sketchy.

 

[Tnfastbk]

"One upside to an iron-based product is that it would be "magnetic" (maybe not the stainless steel but depends on the quality) and able to pass the magnet test."


What is the goal that you are trying to achieve? Maybe I missed it

 

[California 72]

"One upside to an iron-based product is that it would be "magnetic" (maybe not the stainless steel but depends on the quality) and able to pass the magnet test."


What is the goal that you are trying to achieve? Maybe I missed it

It's a nonsensical comment based on the fact that most anyone who has been around for a half dozen decades or more, usually takes a magnet with them when buying a restored classic car. It's not a bad idea for most any car, depending on where you put it. Anyhow, you use the magnet, as carefully and discretely as possible, usually when the seller is looking the other way or you have a person along for the ride distract them, to check for bondo. Those repairs, even the aluminum stuff, the magnet won't stick.

My use is strictly trying to provide the strongest possible mixture to avoid cracking in key stress areas like the fender shirts. I've been thru too many re-fixes after work is completed and I want the finished work to last for the remainder of my life.

I'm not concerned about any "key" areas of repair, i.e. bottoms of fenders, doors, quarters, wheel flares, rocker panels, trunk floor, etc., because when this is sold by our daughter, years down the road, we've already determined they are factory original sheet metal.

 

[Tnfastbk]

I understand the magnet thing I was just curious what you were after in the end. I think most of the modern "Bondo" is a lot better than it used to be. Of coarse if its two inches thick you will more than likely have issues. The following is from a quick search on substitute for bondo I found on another site. NOT MY POST:

THERE'S your problem......
Bondo(tm) is the bottom of the food chain--probably the reason most folks think body filler is total CRAP.

Go to your local P&B supply and get a can of "Rage Extreme" plastic filler. Goes on like butter, sands like talcum powder. It'll CHANGE your life

Use it like 2-toned said--wipe the whole length and block it off. And Icing is great stuff too. Kinda like a cross between filler and primer---spreads like pancake batter and sands great.
Body finishing isn't rocket science, you just gotta use the right tools(yes, filler is a TOOL!

)

 

[Sheriff41]

Skip the Bondo and look into Evercoat products. Evercoat has fillers formulated for different applications and will have one for your needs.

 

[Stanglover]

In the past, I have used a metalized body filler with good success. The downside is it was harder to sand and finish. I'm not sure what company made it but it was sold through Canadian Tire.

 

[72mokk1]

Evercoat Rage Gold is one I have used, it has glass beads added to it for strength. You body filler should never be so thick a magnet won't stick to the metal. You should be able to work the sheet metal well enough so that there is only a thin coat, less than a 1/4 inch. Learn how to "Sheet metal shrink" to remove the Tin Can effect.

 

[Vern Cook]

I don't know what you are trying to fill but have a look at paintless dent removal. Just discovered it myself and having a wonderful time playing round with it. Don't know it's limitations but don't think it would work well on rust.

 

[detritusmaximus]

I don't know what you are trying to fill but have a look at paintless dent removal. Just discovered it myself and having a wonderful time playing round with it. Don't know it's limitations but don't think it would work well on rust.

It's better than dentless paint removal.

 

[California 72]

Basically, there are just a couple simple goals I'm trying to achieve with the filler.

• Something strong enough that even a thin coat, we're talking thin like spot putty, that won't crack under more extreme circumstances.
• Something that will basically clean-up the flaws from my current beginner-level welding abilities and again, not cracking a couple years down the road.
• If someone or something inadvertently leans or applies pressure against the area in question.

Jumping in the way-back machine, when I had my '66, a local Chicago 'burbs Fiberglass shop named VFN, developed fiberglass quarters that several of our group used. No matter how well we finished the area, a crack along the seam started to appear, just from the body torque our engines created. Even a full-frame beast like a '68 Charger wasn't immune to the issue.

While I have no need to replace anything as large as a quarter panel or really larger than maybe a dollar bill, other than the battery fender skirt, only wanting to make certain that when I shoot the paint, the area I do need to use the filler responds without any issues. Basically, whatever is used, it won't be thicker than 1/8" if even that.

While any repair I make will require some form of filler and prep before painting, I could forego the ultra-thin skim coats and use a "feather-fill" type product but the experience with that, if I remember well enough was, it caused some pin-holes itself and required spot putty and an endless amount of sanding too. It really created its own class-level of work to prep for paint. Remember thinking it wasn't the shoot and paint with minimal prep it was marketed under. We are talking 1980ish and yeah, it's probably safe to say it's improved over the last few decades but just getting as much info as possible.

As far as any suggestions for "glass" product, that is verboten for this project. See explanation a few posts back.

 

[TheDude]

As far as any suggestions for "glass" product, that is verboten for this project. See explanation a few posts back.

Is your bad experience with getting itchy from this stuff from working with fiberglass or fiberglass filler? I've personally never had any issues working with glass filler like glass reinforced bondo where working with actual fiberglass I get it bad. I've always found working with the glass reinforced bondo to just create a lot of regular dust like normal bondo. It isn't as smooth as regular filler, so you need to skim coat over it with something smoother either way.

Also, I highly agree with the Evercoat recommendations. Lots of different products, but I've found them all to be a lot easier to work with and leave a better finish.

On just working with regular fiberglass for odd patches and reinforcing things, flannel can work wonders and an alternative. Not going to be quite as strong, but you can add a ton of strength in a very to easy to work with material but without having to deal with the itchy downsides of fiberglass. Again not for every use case, but for a lot of smaller stuff it's way more than enough and your wife will probably thank you for getting rid of one of your old shirts.

 

[California 72]

Is your bad experience with getting itchy from this stuff from working with fiberglass or fiberglass filler? I've personally never had any issues working with glass filler like glass reinforced bondo where working with actual fiberglass I get it bad. I've always found working with the glass reinforced bondo to just create a lot of regular dust like normal bondo. It isn't as smooth as regular filler, so you need to skim coat over it with something smoother either way.

Also, I highly agree with the Evercoat recommendations. Lots of different products, but I've found them all to be a lot easier to work with and leave a better finish.

On just working with regular fiberglass for odd patches and reinforcing things, flannel can work wonders and an alternative. Not going to be quite as strong, but you can add a ton of strength in a very to easy to work with material but without having to deal with the itchy downsides of fiberglass. Again not for every use case, but for a lot of smaller stuff it's way more than enough and your wife will probably thank you for getting rid of one of your old shirts.

It's the glass strands that make up fiberglass. Filler or sheet, when sanded, it throws a fine particulate of glass in the air and permeates everything. The unfortunate side is it also works it's way into the washer and dryer when you do clothes, separate or not, even with repeated rinsing. Just my experience. It's not worth the hassle to mitigate its effects from encapsulating the garage to using a laundromat. Easiest thing is just not use it.
We're also still picking wire brush strands out of everything from its use.
For what it's worth, why create more work than needed? Being retired, you will catch me working as hard as I did in my past life but if I can avoid something, you can bet the Mustang that I'm gonna try to avoid it.
Never heard of flannel before, however, I've used old Tamis (culinary drum sieve) screens or an actual extra fine door and window metal screen.

 

[72mokk1]

I have never felt itchy after using Evercoat, it's not like the fiber glass mat used on a boat or Corvette, which by the way I also dreaded working on. Body fillers have come a long way since the 80's and are much more flexible. Try the aluminum reinforced if you are highly opposed to the glass products. Also, if you have "flexible" panels go to a body shop and see if you can get a wrecked door, fender, deck lid and learn to sheet metal shrink on that. Nothing will protect the hood from butt prints but your quarters shouldn't pop in and out.

 

[TheDude]

I have never felt itchy after using Evercoat, it's not like the fiber glass mat used on a boat or Corvette, which by the way I also dreaded working on. Body fillers have come a long way since the 80's and are much more flexible. Try the aluminum reinforced if you are highly opposed to the glass products. Also, if you have "flexible" panels go to a body shop and see if you can get a wrecked door, fender, deck lid and learn to sheet metal shrink on that. Nothing will protect the hood from butt prints but your quarters shouldn't pop in and out.

Same here. I've had that stuff covering me head to toe after a few boat repairs and it felt and acted like regular filler dust. For me anyway, no itchiness and was very strong. I've definitely had and hated that issue when cutting or sanding actual fiber glass parts.

 

[72mokk1]

Same here. I've had that stuff covering me head to toe after a few boat repairs and it felt and acted like regular filler dust. For me anyway, no itchiness and was very strong. I've definitely had and hated that issue when cutting or sanding actual fiber glass parts.

Agreed, I get itchy looking at fiber glass.