TheSamba.com :: View topic

Wed Feb 08, 2017 10:41 am

I have a question for those that have redone their old pans. Not replaced, but cleaned up and repainted/undercoated. Besides a nice bead blaster, which I don't have, what method did you find worked best to get all the old stuff off the bottom. I am currently using my angle grinder with a wheel on it, but am wondering if there are faster/easier methods. I'm not apposed to this method, but as I don't know a better way I figured I would ask.

Thanks.

Wed Feb 08, 2017 11:43 am

Nope...that's about it. A wire wheel and lots of time.

Wed Feb 08, 2017 3:24 pm

I use a gearless angle diegrinder with a cupped brush. Spray oil or spraying a little water on the metal helps remove rust while doing this. A regular die grinder should be just as good as long as it has some power or even a drill. An automatic center punch removes scale on metal but it will make holes if the metal is too thin.

Phosphoric acid available at homecenters works good but you have to have patients. I have been trying to nail the perfect method down but rust is not rust. One method that I have been using is applying phosphoric acid on in coats and letting it dry until a point where it is black. Then I start doing the same thing with muriatic acid on spots where the phosphoric acid has stopped working. There comes a point with thick scale where phosphoric acid stops working and the method has to change.

You have to have good ventilation and be careful not to slop the acid around and make it airborne or be under it if it drips. It's not that dangerous if you follow a safe procedure and don't wander from it. Use goggles and keep a spray bottle of water that you periodically make sure is working close by just in case.

Thu Feb 09, 2017 4:00 pm

Thanks for the replies. I have been doing the 4 1/2 dewalt angle grinder with cupped brush. It comes off, but wanted to not kick my self in the ass when completed by someone saying I should have done it XXX way.

Thu Feb 09, 2017 6:19 pm

I stripped my pan with the same thing, it takes a while.
the thing is a wire wheel will remove all the dirt, paint and 99% of the rust, put at a certain point it just polishes the metal and rust, leaving that last little bit of deep black "root' of the rust, sandblasting is really the best, but as I'm on a tiny budget, and was painting on por15 top coat, I use their metal ready acid etch stuff, so far so good, will it last? ask me in 10 years.

back braking work!

this was the metal ready converting the last of the rust black.

and after paint.

good luck.

Thu Feb 09, 2017 7:06 pm

By the way....the POR metal ready product just mentioned...IS....a phosphoric acid and zinc phosphate based prep similar to what TheKbStockpiler noted......but it's pretty weak....so its mainly just a light prep as mentioned to get the very last fine traces of rust converted before paint or coating.

It does not have enough strength to do beavt derusting lime stronger phosphoric acid mixtures.

Ray