Anybody skilled on car finishes ?

[Rick Hughes]

I have a twin boat trailer, only 2 Yrs old and the dreaded rust started on wheels ... Even though these trailers cost almost £5k ... they don't like salt water that much. I don't want to do the standard approach of painting on Hammerite - it is simply no good on marine trailers ...

Pic of minor wheel corrosion here ...

As it's out of season want to attend to these, my plan is: # wire brush off all rust, and overall key surface # wash down well to remove any oil # spray 2 coats of UPOL #8 Acid Etch Primer # spray 3 coats of extra durable wheel # spray 2 coats clear lacquer

That would with the exception of shot blast back to bare metal seems to me to be a good approach.

One thought I had was after wire brushing off rust, applying Ku-Rust, but when I asked Ku-Rust technical they advised if that was case I would have to forgo an acid based primer as that would lift off any KU-rust treated parts.

Anybody got any tips or suggestions on above approach ?

[polygonum]

If I were you, I'd continue with what you did re Ku-Rust, contact manufacturers' technical departments. Some are very helpful.

[Huge]

And the answer is ... POR15.

[Adrian]

If they're going to be dipped in salt water regularly, then you're really pissing in the wind with aerosols. Even if you remove the tyres (which you've not mentioned), there's a strong likelihood of damaging the paint on the rim when you get the tyres refitted.

The nearest you'll get to any long-term corrosion resistance is getting them blasted and galvanised.

[Rick Hughes]

Was going to let air out ... so I can push rubber away from rims, enough to slide card under to mask off tyre while painting.

It is annoying that when you buy an expensive galvanized trailer, the wheels are just painted steel.

[Adrian]

Considering that between tyre and rim is a great place for salt water to get and, quite possibly, sit semi-undisturbed, you'd really want to break the bead properly to get in and clean it up properly.

You've got three choices.

Galv 'em. Leave 'em manky. Pretty them up, but accept that in a year you'll need to redo 'em again. And again. And again.

Galvanising _might_ bring balance issues. I don't think it will at trailer speeds - there's a few people on a forum I'm on who've had campervan steels blasted and galv'd, and reported no issues - but it _might_.

You might want to investigate whether you can buy new galvanised rims. It may well be cheaper and easier than galvanising your existing rims.

[Rick Hughes]

As I have bought the paint, a paint finish is the way fwd .... I change boat & trailer about every 3-4 yrs, so if they last 2 yrs then great.

I'd like the nice alloy ones they fit on US trailers or even powder coat them ... but maybe next time from new.

[Adrian]

Ah, you didn't mention that bit...

Electrolytic corrosion to the hub...?

[Rick Hughes]

The Yank trailers seem to use them OK ... but get your concern.

Maybe powder coat is a way fwd next time for me.

[Adrian]

Sounds like the worst possible for a wheel rim, tbh. As soon as the powder gets breached somewhere - dead easy by kerbing, mounting a tyre, wheelnuts etc etc etc - then the salt water has nice bright steel to get at, and it'll just creep under the plastic until - one day - the coating just peels off in one big sheet, since there's not much steel underneath it any more.

Nah, galv. If it's good 'nuff for the trailer chassis...

[tony sayer]

Galvanised each and every time for proper steel protection.

We have in use a lot of aerial bits and pieces up high masts and towers anything if painted or power coated will rust thru in no time even if it isn't chipped or scratched. Some gear has been up for 30 years and its still OK if it was Galv of course:)...

[Rick Hughes]

It's annoying they don't fit Galv wheels on a Galv chassis

[Rick Hughes]

Asked UPOL for advice .... they re incredibly helpful ... same day reply, explanations for their chief chemist, data sheets ... impressed with them.

They advised steps I had thought with addition of after the acid etch primer add 2 coats of High Build primer (I'll use their UPOL #5) .. they advise acid etch gives a good adhesive but no protection .. easily damaged .. hence high build primer on top.

[polygonum]

Glad they were. And interesting approach.

[Rick Hughes]

OK guys you have convinced me, just taken 4 wheel off trailer ... having them Galvanized ... £30 for the ... plus whatever they charge for grit blasting. (£30 -50 depending on time)

[Adrian]

That price for five? Or each?

[Tim+]

How smooth is a galvanised finish? Just thinking about bead sealing with tubeless tyres. Might need tubes.

Tim

[John Williamson]

If it's up to the normal standard, most tyre depots have some sort of goop (A technical term)they use for sealing porous and corroded alloy wheels which will do the job.

[Rick Hughes]

My other boat trailers had Galv wheels with tubeless tyres Good point to raise though

[Rick Hughes]

£30 for the 4

That is less the same as the cans of paint were costing .. but the grit blasting will be on top of that.

Acid etch primer > High Build Primer > Paint > Laquer