[electroubleshooter]

I used muriatic acid and Limeaway to remove the rust from this chassis. I am now using a die grinder and scotch brite discs to shine it the rest of the way.
It has some deep pits. Can I fill these with Bondo? Or should I try lead solder? Also, the acid left black spots in these pits, is this a problem?

What is a good paint to make a Philco look original or near it?

Guess I will have to paint the IF transformers to match?

[Ron Ramirez]

Hi

Yes, I see no reason why you couldn't use Bondo to smooth out your chassis. try to find a flat silver paint to repaint the chassis with. I found some Valspar spray paint at Lowe's in flat silver; it looks pretty good, much better than that aluminum paint that does not look at all original.

The black spots are probably a result of the treatment you used on the chassis, clean the chassis as best as you can, primer and then paint with flat silver as mentioned above.

The IF transformer cans should be aluminum, and will respond quite well to the aluminum polish that looks like cotton wadding (mag wheel polish or equivalent). You tear a small piece of wadding off and use that to rub out the can really well, then polish with an old soft cloth or even a paper towel.

[gary rabbitt]

Hi,
I'd stay away from the Bondo unless you have rusted thru places. To use Bondo, it is recommended that you grind and roughen up the area to be filled. You don't want to grind your chassis up like that. Applying Bondo to a slick or smooth surface may result in the stuff peeling or flaking/not ahering to the metal.

As an alternative, when you are ready to start painting, use a coat of primer (after prepping properly), Use it over the small pits.
Once you have the primer on, you use "sopt putty", comes in a tube from auto body suppliers.
The primer gives the spot putty something to grip to. If you apply putty to bare metal it will not hold.

After it's dry, block sand the spot putty level with the surounding areas.
You can add another very light mist of primer over the levelled out pits now.

Go ahead and do the painting. I agree that the bright aluminum or silver paint is gaudy and should be avoided at all costs You don't want something to blind you whenyou look at the back of the set.
The flat silver or even a silver grey will look good.

Many use Bondo for cabinet repair and such but Bondo was not made for a structural material. It either must have a bast to be applied to, or needs to be backed up with something more solid. A missing piece of cabinet filled with Bondo , and not backed up will eventually fail,or get hairlines where the repair was made. In fact for auto use, Bondo is not recommended for deep repairs like a large dent,. The less you need, the better. A thin coat is preferred after the netal is brought out as close as possib;e to original.

For structural repairs fiberglass colth, and resins are preferred. It is easy to flow 'glass resin on the inside, beyond the repair area for added strength.

Sorry for straying on the subject, it's late.
Take care,
Gary.

[electroubleshooter]

Thanks Gentlemen

[Ron Ramirez]

You can put Bondo down on bare metal. The chassis in question is, by electroubleshooter's own description, already rough, so adherence should not be a problem.

Two examples of this being done in automotive work:
http://www.purplesagetradingpost.com/sum...aint1.html
http://www.a2zautoforums.com/showthread.php?t=936

I've done a little bodywork before, and I will be the first to agree that Bondo is not good for deep, structural repairs (i.e. large holes or dents). Nevertheless, several years ago, I owned a 1974 Oldsmobile Custom Cruiser with rust around the wheel openings. Yes, I filled the holes with Bondo, using fiberglass sheets as a backing, then primed and painted. Surprisingly, it held up - and much better than I ever expected it to; the stuff was still adhering when the car's engine threw a rod a couple years later, and I sold the car for scrap.

A radio chassis is not going to be subjected to the extremes of an automobile; it will remain indoors in a controlled environment. Therefore, flaking and peeling should not be an issue, and either Bondo or the spot putty would be O.K. in this application.

[audin]

The black is exactly what the muriatic acid is supposed to do. That is the black iron oxide that is desired since it does not attract water like red iron oxide will.

[auplater]

"The black is exactly what the muriatic acid is supposed to do. That is the black iron oxide that is desired since it does not attract water like red iron oxide will."

Uh.. no. the black crud left in the pits is a mix of iron rust, iron particles, carbon and other insolubles from the steel. Also contains chloride, a very bad actor towards future corrosion problems. Best not to use muriatic acid AT ALL to strip chasis, phosphoric acid (Naval Jelly, etc. type de-rusters) produces an iron phosphate type film that inhibits future corrosion and makes for an excellent post paint base after rinsing.

As for cleaning up the muriatic stripped chasis, you need to neutralize the surface with bicarb soln. (Baking Soda) and rinse well. Otherwise, a few years down the road, those "black oxide pits" will come back to haunt you...

From an electrochemist who's been in the industry for 40+ years.

John L.

[Guest]

Try USC Duraglas part no. 24030 at Auto paint supply stores, It sticks to anything will, not shrink, water proof, strong, sands hard, can be painted after priming. Used it on the studebaker for over 15 yrs ago no problems. Don

[jayoungs]

This may be way off the mark, but I just noticed and bought some Rust-O-Leum "galvanizing" spray paint from Home Depot. I have a couple of non-radio projects I plan to use it on, but would the galvanized color work okay for a chassis? Seems to me would be a good fit, but would like the experts' opinions. I want to be as close to "original" as possible. Thanks.