Rust removal using acid bath?

[boggie]

Hi All,

 

I have two second hand doors, found in a farmer's barn that I am restoring. Along the bottom, where the door skin is folded and welded, there is quite a lot of rust. I bought a length of square guttering and a couple of end caps and made a simple bath by cutting to size and sealing the end caps on with "serious Stuff" adhesive. I had planned to fill this bath with phosphoric acid and stand the doors in it overnight to kill all the rust. However, whilst looking for a suitable supplier of the acid I found myself faced with a wide selection of strengths and types. Then to compound my confusion I found manufacturers of alternative products saying that using phosphoric acid was bad because of complications neutalising the acid with water or difficulties painting etc.

 

So, I need the advice of all you experienced rust-busters. What is the best product to fill my bath with? I want it thin enough to flow into all the nooks and crannys, kill the rust for good, be easy to paint over and no more than £50 a gallon. Any ideas?

 

Many thanks,

Ian

[Rhodri]

http://www.stovebolt...c_derusting.htm

 

How about this, never tried it myself?

 

Rod

[stuart]

Jenolite works very well and is inert once dry.

Stuart.

[Ian Vincent]

I use Bilt Hamber rust remover and it is absolutely brilliant stuff. It has the advantage that even if you leave something in it for too long (as in weeks) it doesn't destroy it.

 

They do two versions, a gel paste for large items that won't go in a bath and white powder which you mix with water as a soaking medium. The same solution can be used over and over until it is 'worn out'.

 

Rgds Ian

[Guest DeBartolomeis]

I used the acid-bath for my 1959 tr3a in 1994. Boy, it was funny when I took it to the shop. All the workers were in aw in how clean it was. It looked brand new, ready for paint. Unfortunatley, in 2000 i think the federal economic administration banned the acid-baths because of heavy polution. Im not sure if there are still running today.

[TR Doctor]

Go back to the farmer and get some "Milk Stone Remover" (<$10 per gal U.S.) which is phosphoric acid and some detergent. I believe it is diluted 1:10. You could always neuralize with baking soda. Then POR 15 and a top coat of primer when still tackey. It will not rust again and then you can use a little bit of filler to smooth out the pits.

 

Paul

(Son of a dairy farmer)

[john.r.davies]

Go back to the farmer and get some "Milk Stone Remover" (<$10 per gal U.S.) which is phosphoric acid and some detergent. I believe it is diluted 1:10. You could always neuralize with baking soda. Then POR 15 and a top coat of primer when still tackey. It will not rust again and then you can use a little bit of filler to smooth out the pits.

 

Paul

(Son of a dairy farmer)

 

I agree with Paul (though grrrrrrrrrrr! Even dairy farmers benefit from the tendency to price things in dollars and pounds at the same number)

The difference for phosphoric acid is that unlike mineral acids, iron phosphate is relatively insoluble, so a layer of phophate builds up on the surface, sealing it and providing a good key for the first layer of paint. Disadvantaage is that the layer must be wire brushed off to deal with deep rust.

So it's horses for courses - if your doors are rusted badly, mineral acid first, but be cautious. Meinral acid is just as good at dissoliving metal as it dissolves rust!

John

[boggie]

Thanks Guys!

 

I will get some Phosphoric 10% and leave them to soak. How long is safe? I don't want to find I have dissolved the doors overnight!

 

Cheers,

Ian