epoxy primer - OK for long-term storage?

[gasket999]

Hi folks.

Some time ago I had a large car panel made for me (its a Land Rover bulkhead). Its in Zintex steel (all new, not a refurb) with some exposed areas and I've been storing it in the house for over two years (the Mrs. hates it), frantically worrying about it flash-rusting before I had chance to get it treated. Its all good so far.

Anyway - its going up the road to be lightly blasted and then hot-zinc sprayed. Ultimately I'll be respraying it in body colour (1k or cellulose).

In the meantime, the firm that's doing the zinc spraying can also epoxy-prime it for me after the zinc - which as a primer would be better than anything I could add with the compressor in the garage. It'll probably be a year or so before I get round to painting it - I know what I'm like in that respect.

So the query is, is epoxy primer stable enough to leave for a year before painting over? If not, I'll just take it back in the bare zinc.

My understanding is that, unlike traditional primers that are hydroscopic/porus epoxy primer is effectively unaffected by moisture and doesn't care if its left for a long time. But I'd welcome some confirmation of this.

The panel was very expensive and I don't want to cock it up.

Thank you.

 

[fizzy]

Hi folks.

Some time ago I had a large car panel made for me (its a Land Rover bulkhead). Its in Zintex steel (all new, not a refurb) with some exposed areas and I've been storing it in the house for over two years (the Mrs. hates it), frantically worrying about it flash-rusting before I had chance to get it treated. Its all good so far.

Anyway - its going up the road to be lightly blasted and then hot-zinc sprayed. Ultimately I'll be respraying it in body colour (1k or cellulose).

In the meantime, the firm that's doing the zinc spraying can also epoxy-prime it for me after the zinc - which as a primer would be better than anything I could add with the compressor in the garage. It'll probably be a year or so before I get round to painting it - I know what I'm like in that respect.

So the query is, is epoxy primer stable enough to leave for a year before painting over? If not, I'll just take it back in the bare zinc.

My understanding is that, unlike traditional primers that are hydroscopic/porus epoxy primer is effectively unaffected by moisture and doesn't care if its left for a long time. But I'd welcome some confirmation of this.

The panel was very expensive and I don't want to cock it up.

Thank you.

Epoxy primers are used on oil rigs and will last for 20 years!

 

[Dcal]

It will be absolutely fine and epoxy is the best primer for galv.
As fizzy say it will work as a top coat but I’d say it’s put on a bit thicker on oil rigs.
When you do go to paint over it, make sure it’s clean and well sanded, especially if it’s been sitting for a while.

 

[tigdlo]

No issues with moisture but most epoxies have poor UV resistance, so keep it out of sunlight or cover it up.

 

[Matchless]

I used white epoxy primer as a primer / top coat on my Transit repairs recently, I discovered a couple of mig welds that needed grinding down the day after painting, I used a rough disc on my 5" grinder, the metal went blue but the primer never bubbled, lifted or even discoloured right next to the grinding! I was well impressed, I fully expected it to burn and lift for an inch each side....

 

[Dcal]

No issues with moisture but most epoxies have poor UV resistance, so keep it out of sunlight or cover it up.

It will chalk in strong sunlight but it won’t affect the performance.
When you sand it, the chalking will be removed anyway and it will give you a good indication that you haven’t missed a bit.

But I agree, no need to have if sitting outside.

 

[optima21]

so far I havnt had issues with chalking with jotun 87, and I couldn't find any mention of it on their data sheets, on the underside of my cars its all I use, just the jotun 87, no top coat or stonechip and its holding up pretty well.

 

[bricol]

Black goes grey exposed to sunlight and weather - still stuck to blasted steel like sticky poo to a hairy blanket

 

[gasket999]

Ace! Thanks guys. Looks like I've got a way forward.

It'll be stored out of UV light in a dark garage.

 

[OJCar]

If it is made in Zintec why are you getting it blasted?

Just get it epoxy primered.

 

[Dcal]

Zinc is not an easy metal to get paint to stick to.
A sweep blast will really help improve adhesion.

 

[Dcal]

The industry standard for the highest exposure class (C5M) for painting galvanised steel is a sweep blast followed by epoxy.
It's probably overkill for a car body and the coatings won't be thick enough, but why not.

If you flex a factory painted zinc coated car panel, it's very easy to get the paint to flake off the metal.
Try the same thing with a steel panel and it sticks far better.

Epoxy is the way to go whether you blast or not.

 

[gasket999]

Thanks guys.

I'm having the panel hot-zinc sprayed. I've had far too many Land ROver bulkheads rot over the years to take any chances. Equally I've hot-dip galvanised a few and the results have been a mixed bag. With this one being newly made and expensive, I'm not taking any chances with the hot dip so I'm having it hot zinc sprayed instead and filled with cavity wax.

Usually, when I have them hot dipped I use T-wash/mordant solution as mentioned above prior to etch prime and paint.

The blasting is, as mentioned above is in this case simply a very light sweep to get better adhesion for the hot zinc spray. The company offered to epoxy prime it too for minimal money - hence the interest. I'd assume there'll be some sort of prep (T-wash) before hand but I will of course check with them.

The epoxy primer is basically just to save me the job of priming it myself, I'm relying on the zinc spray to give it corrosion protection - with the primer and paint serving to protect the thin zinc coating.

 

[OJCar]

Zintec is easy to get epoxy to stick to, degrease then paint.

Zinc Plating & Galvenising needs more treatment such as T-wash (Mordant) or a light blast before expoy .

Zintec and Zinc Plating are not the same thing.

 

[gasket999]

Thanks OJ. The panel was fabricated in Zintec originally. The hot-zinc spray and epoxy primer is a further addition for belt-and braces protection.