Hello All,
I'm working on a 38-116 and the chassis is a little rusty here and there. I'd like to clean it up and make it look nice again, but I'd also like to protect it. Was looking for some suggestions about how to do that. I was planning on using Naval Jelly to clean up the rust. Wipe down well and then spray on a coating of WD40. Will that method hold up well? Also thought about spraying with lacquer. What do you all recommend?
Matt
No. The WD-40 will evaporate - mostly. What is left will not protect for long but it will make replating or painting difficult.
If you just have small spots, use the jelly carefully since it is very good at removing plating which will make future rusty spots bigger. Then get some silver paint, the old stuff has a greenish tint - NOT CHROME (paint) - and wipe it on with a small brush (I use my finger) like stain, only on the small spot. Blend a little (easier with finger) and try to leave as much of the original plating in place as possible. Clean off finger.
If your chassis is SO rusty as to need to be completely painted, find another chassis. If the chassis was originally painted - repaint it.
Caswell sells brush-on plating kits, mostly for copper and nickel. These can be used to replate small spots and work very well - yes you can sometimes tell where the spot was fixed. I use this method to plate the solder joints on re-stuffed Mershon caps. Works great. Just used the nickel brush to do a small spot on the AK 82 chassis I was working on.
I think that a lot of early Philco chassis were zinc plated - turns dark grey. If you are going to touch up one of these silver isn't the right color. I do have some "cast" color in a spray can. It is a better match. Though I have had it for 15 years or so, it is probably still available at car parts stores. (That is cast - as in cast iron)
That is paint, so is clear (paint).
As Russ mentioned, after you do the naval jelly rust removal you will have a bare metal that will be shiny, bright and a different color than the surrounding zinc coated metal. By painting the small area you derusted with silver (I have mixed silver, green and sometimes a touch of black to try and match the zinc color) it looks closer to original than a clear paint, lacquer or whatever material you choose.
Here is the thing about painting a chassis that was originally unpainted.
First, it is hard to do. If you can remove all of the components, then you can do a paint job like it should be done. It is really hard to get a good job when you are just masking-off transformers, tubes sockets and such. But if you are going to remove all of the components, you might as well have the chassis replated (not to be confused with chroming though that may be the plating on some chassis)
Now, if restoration to a factory appearance is not important, then you are probably not going to the effort of stuffing caps and such. Then painting the chassis might be acceptable but there is really no reason to go to all of the work on the underside if the chassis is to be painted since just about anybody is going to be able to tell that it is not original.
When painting a rusty chassis care should be given to ground connections that rust or paint might insulate.
It occurred to me last night that this should be added for newbies:
SOME CHASSIS AND PARTS ARE PLATED WITH CADMIUM. CADMIUM IS VERY POISIONOUS. FRIABLE (DUST) MATERIAL CAN BE INHALED. THIS MUST BE AVOIDED. SANDING A CADIMIUM PLATED CHASSIS IS UNSAFE AND MUST BE AVOIDED.
Try using a derusting/iron phosphating chemical like chemtex or Captain Lee's rust away.
They'll remove the rust and leave behind a grey iron phosphate coating that is mildly corrosion resistant (also an ideal surface for repainting or powdercoating).
Any decent automotive paint shop will have products for this type of application. POR-15 is a good product that I get at my paint shop.
Eastwood has a product called After Blast that leaves a zinc phosphate coating, that's even better at preventing future rust formation. That would be an excellent follow up to navel jelly.
Never, ever, using Muriatic or any form of hydrochloric acid to remove rust. Yes, it does so quickly and at first glance efficiently, but it leaves behind Cl ions that bond to the steel and merrily kick out out carbon molecules to be replaced by oxygen molecules and the rust goes on and on and on...(it's the Cl in NaCl (roadsalt) that makes cars disappear).
Recently I painted mine removing all parts I could, derusting with special product like POR-15 and masking the left things, will not look like factory zinc platting but will preserve the chasis for future restorers
zinc platting diy is easy with a battery charger and a piece of zinc if you will remove all. Any path you choose will be good if you preserve for further rust damage.