REALLY, THEY STILL USE BONDO?

[Jimmie]

A fellow came to my house this afternoon to give me a bid on repairing rusted areas and painting my "50" Champion. He took notes and is to let me know how much he will charge.

He plans to weld in new pieces of metal where needed and then use bondo to finish the area to its orininal shape. I told him that I had had a bad experience with bondo collecting water and the paint flaking off. He assured me that the metal he welds in will seal the back side of the bondo and therefore no water can get to the bondo.

Isn't there some better way to do this than using Bondo as a filler or am I just being too careful or maybe just ignorant of how things are done?

Jimmie


1950 CHAMPION -ORANGE COUNTY, INDIANA
I'VE SAVED SO MUCH DAYLIGHT THAT THERE'S NO DARK TO SLEEP IN ANYMORE!

[JDP]

Body putty, poorly applied can cause problems. Applied correctly by a pro, it'll last almost forever. If you could see how almost a entire car is skim coated in a high dollar restoration, you'd realize how well it works done correctly.

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

[Swifster]

Bondo is the name brand of a plastic filler. Every body shop uses filler for repairs. No one metal finishes anymore (there are a few oldtimers...). Nothing wrong with the stuff if used and applied correctly. You also have to paint reasonably soon after being applied. You can't leave it open to the weather. Heck, every new car has filler where panels are joined (roof to quarter panels for example).

---------------------------------------------------------------------------------------------------
Tom - Mulberry, FL

1964 Studebaker Daytona - 289 4V, 4-Speed (Cost To Date: $2125.60)

[rockne10]

Good metal patching will require as little filler as possible. I use Dura-glass initially. It sets harder and is moisture proof. Softer setting and more easily workable bondo as a top coat for primary contouring. Getting your initial metal repair as close as possible assures the thinest filler and the least labor. Seal behind with 3M Flexi-clear seam sealer.

[54-61-62]

Using some filler is okay to skim joints or patches, but one should not make new parts out of bondo or use it to majorly contour poorly fitted patch panels.

[Mike Van Veghten]

You guys....

Most all high end bodyshops use "bondo" (generic name nowdays) to skim coat the entire car!
Delahays, Delages, Bentleys, Bugattis, Pierce Arrows....obviously all high end cars...all with a plastic filler!

I know for a fact a Delahay a friend worked on (the exhaust system) won second place in one of those "on the green" car shows, it was at one time covered in plastic filler as the finish body work was being completed.

There is a shop in San Diego (CA.)...that works these high end cars only...that when the body work is done, the entire car gets a layer of plastic filler...this includes the door jam gap, the hood to fender gap, the trunk to body gap...
They sand the car as though it was a block of wood, THEN open all of the door, hood, etc., and all other non-filled body lines.

Plastic fillers have come a long way in the last 6 or 8 years.

Mike

[Blue 15G]

You mean you're supposed to prepare the surface before you apply it? [:0]

Dave Bonn
'54 Champion Starliner

[52 Ragtop]

Plastic filler is "supposed" to be used as a skim coat to smooth out the imperfections in the metal. Bondo is a "namebrand" and available at places like Wal-mart. A good plastic filler will run about $22 per gallon. The metals on cars today is thin and is not repaired by metal finishing or lead. In fact there are very few of us around that can lead and metal finish!
Also, once you have your filler properly sanded, do not let it get wet! as the moisture will get behind the filler and start the rusting process all over again.
And remember, primer is NOT waterproof! so don't shoot some primer over the repairs and set it outside, as it will rust again.
Surface preperation is the key! also make sure that the patch is sealed from the back too.
My advice is to use the best materials you can buy, and stick with the same manufacturer of the top coat and use their system from the etching primer to the color coat and clears. DO NOT mix brands of primer and paint!

Jim

[Pat Dilling]

quote:Originally posted by Mike Van Veghten

You guys....

Most all high end bodyshops use "bondo" (generic name nowdays) to skim coat the entire car!
Delahays, Delages, Bentleys, Bugattis, Pierce Arrows....obviously all high end cars...all with a plastic filler!

I know for a fact a Delahay a friend worked on (the exhaust system) won second place in one of those "on the green" car shows, it was at one time covered in plastic filler as the finish body work was being completed.

There is a shop in San Diego (CA.)...that works these high end cars only...that when the body work is done, the entire car gets a layer of plastic filler...this includes the door jam gap, the hood to fender gap, the trunk to body gap...
They sand the car as though it was a block of wood, THEN open all of the door, hood, etc., and all other non-filled body lines.

Plastic fillers have come a long way in the last 6 or 8 years.

Mike

I heard a relevant quote to this. A guy was talking to the owner of one of those beautiful cars with all the gaps perfect and not a wave in the panels and asked: "What did you use to get the body so straight?" "Hundred dollar bills." was the reply. Applied properly and in limited thickness, plastic filler and proper sanding will get well prepared panels straighter than pure metal work alone.

Pat

Pat Dilling
Olivehurst, CA
Custom '53 Starlight aka Stu Cool

[N8N]

the deal with the filler drawing water and causing rust is no joke. The deal is, it is supposed to be used exactly as described in this thread - a metal patch is welded in and then the Bondo is used as a skim coat to finish the surface. It MUST be applied over an area that has NO HOLES in it. If that is done, and then the filler is sealed with an epoxy primer, there's no issue. (also, he should paint the backside of the metal patch with something to prevent rust there, as well.)

Where it gets a bad rap is if someone uses it over a surface with pinholes in it or bad welds where water can get to the backside of the patch - that will cause rust faster than doing nothing at all!

nate

--
55 Commander Starlight

http://members.cox.net/njnagel

[showbizkid]

Illustration of an improper use of filler: the battery shelf on my Lark rusted out a while back. Some bright boy put in a sheet of fiberglas mat and Bondo'd over it. Now there's mucho rust under the Bondo that hasn't fallen out, and I will have much more welding to do than the PO would have.


[img=left]http://members.cox.net/clarknovak/lark.gif[/img=left]

Clark in San Diego
'63 F2/Lark Standard

http://studeblogger.blogspot.com

https://www.studebakersandiego.com

[Chris Pile]

Could be worse.... I have a rod builder friend who had a customer that brought in a spanking new fiberglass '32 body to be fitted to his '32 rails. The guy said, "and I don't want any bondo used on this body - just old school lead work, OK?"

Chris Pile
Midway Chapter SDC
The Studebaker Special

[BobPalma]

I haven't seen it mentioned here and I know little about body work, but do know this: Plastic Filler must not be applied over brazed repairs! Braze materials, even if waterproofed on the backside, will interact with the filler and lift the filler. Experience is the best teacher, even if it was 30 years ago![xx(] BP

[garyash]

So, Nate, I can't weld well enough to make a perfect seam without pinholes in patches and panel repairs. I was planning on spraying primer on the back side and undercoating after Bondoing and priming the front side with finish paint later on the front. For large gaps and seams in areas that don't need shiny paint, I was planning on using 3M Brushable Seam Sealer, then paint. Shouldn't painting the back side be enough to keep the water out of the Bondo? What else should be done?

[img=left]http://www.studegarage.com/images/gary_ash_m5_sm.jpg[/img=left] Gary Ash
Dartmouth, Mass.
'48 M5
'65 Wagonaire Commander
'63 Wagonaire Standard
web site at http://www.studegarage.com

[54-61-62]

I'd use a water-proof filler for the first coat if your welds have pinholes. USC all metal, or the similar Evercoat product both are excellent for that purpose. Painting the backside will not alone keep moisture out if the welds are pin-holy.

quote:Originally posted by garyash

Shouldn't painting the back side be enough to keep the water out of the Bondo? What else should be done?