treating trailer rust pitting

muncedog

Seaman
Joined
Nov 13, 2014
Messages
67
Hi all,
so my trailer has a fair amount of rust on it in sections. I used sanding/grinding discs on angle grinder to get the majority of. There are many tiny (say 1mm) pittings left. To remove these will require a LOT of grinding and material loss.

I fear for using zinc spray( cold galv) as it will blister on the pitting?
Could I use rust converter, wait a week or so for its reaction to take place, wash thoroughly and then zinc?

Otherwise some acid to remove pitting then wash and zinc?

Otherwise any suggestions please eg regular metal primer and top coat and protective film/oil?

Cheers
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Buy some rust converter. I forget the name of it but it is commercially available. It converts the rust into a hard black coating that can be painted over. Don't know if it can be galvanized over but I suspect not
 

muncedog

Seaman
Joined
Nov 13, 2014
Messages
67
Guess I sort of answered my own question - not wanting to brush back further makes it unsuitable for zinc spray. Rust converter is then the option but that also doesn't allow zinc spray!

Question - has anyone has experience/ luck with rust remover - such as phosphoric acid? I guess this may then stop the rusting process and allow zinc coating to perform better?
 

foodfisher

Captain
Joined
Feb 18, 2009
Messages
3,756
I'm having good luck with Loctite rust restorer. It turns rust into a paintable surface, using a rustoleum product. Not a smooth surface but presentable. Don't know about zink or galvanized coatings.
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,454
Whoever painted that trailer originally didn't paint over clean metal. You need to take that old paint off.
 

gm280

Supreme Mariner
Joined
Jun 26, 2011
Messages
14,585
Research some other trailer rebuilds on these forums and see what others have done. I totally rebuild a trailer and you can see it in my signature link below. It came out like a totally new trailer. And rust is going to have to work really hard to start on that trailer again... There are other finishes that will last as long or longer then any galvanized trailer could. JMHO!
 

muncedog

Seaman
Joined
Nov 13, 2014
Messages
67
Whoever painted that trailer originally didn't paint over clean metal. You need to take that old paint off.

Little bit confused by this? Are you saying this because rust pitting wouldn't occur if they had painted over clean metal?
I was pretty sure the existing coating was the original galvinisation rather than a paint?

meant wire wheel.... That will take the rust out of the pits and leave you with a clean surface.

I have tried a wire cup on a drill but perhaps the wire wheel will have more grunt on an angle grinder! I do wonder if the pitting is too small though - around 1mm might be hard to dig out!

I'm having good luck with Loctite rust restorer. It turns rust into a paintable surface, using a rustoleum product. Not a smooth surface but presentable. Don't know about zink or galvanized coatings.

Thanks for this - might be similar to the rust converter I have - I guess I just had the idea of sticking with Zinc where I can as if I understand correctly it not only seals it but acts as a sacrificial anode - perhaps helping save the inside of the tube sections also!

Thanks everyone for your help - some great knowledge here - I have a feeling the trailer repair might be a mix of different coats - I will let you know what works best - A test run!
 

JASinIL2006

Vice Admiral
Joined
Feb 10, 2012
Messages
5,524
When I repainted my trailer last year, I had a lot of spots with that sort of pitting, too. Never was able to get it totally clean with a wire wheel (cupped or otherwise) and grinding was too much work considering how much of the trailer was pitted. I looked into the rust removers (e.g., phosporic) but they looked like a pain. Since I was only painting, I just went with Rustoleum Rust Reformer. It not only took care of the rust, it also serves as a primer for painting.

I've used the Rust Reformer in other places (e.g., rusting steel I-beams under our cabin) and it really does an excellent job of stopping the rust. I think it's pretty good stuff. I don't think it would work at all if you're absolutely sold on some sort of zinc application, but if painting is a possibility, using Rust Reformer is a pretty good option.
 

WIMUSKY

Moderator
Staff member
Joined
Sep 26, 2009
Messages
19,789
There's various rust encapsulators out there, I've used POR15 with good results. Brush it on and it smooths out to a nice even finish..... Eastwood is supposed to be a good product too....
 

JimS123

Fleet Admiral
Joined
Jul 27, 2007
Messages
7,952
Wire brush with a drill, coat with Rustoleum's "Rust Reformer", then topcoat with Rustoleum enamel - tip and roll.

I used to have an old trailer that was almost solid rust. After doing the above 24 years later it still didn't have a spot of rust on it, even with mostly outdoor storage. Fresh water use only,though.
 

superbenk

Commander
Joined
Oct 27, 2008
Messages
2,022
i was going to suggest POR-15 as well. Looks like the best, most durable product for the job. Rust Reformer seems to work well too, but you still need to coat the results really thoroughly to keep future moisture out. I think POR-15 takes care of both steps at once.
 

MTboatguy

Fleet Admiral
Joined
Jul 8, 2010
Messages
8,988
I normally just knock the loose scale off and then paint with Hammerrite, been doing that for years on various types of trailers with no problems at all.
 
Top