Bare sheet metalwork protection - Epoxy primer?
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Bare sheet metalwork protection

I seem to be pretty lucky in my garage as far as bare metal not getting rusty, the garage is built as part of the house so is effectively heated on 3 sides....

However I now want to start finishing certain areas off ready to be prepped at a later date so I want to paint / prime these areas in such a way that they are protected from surface rust.

From what I've read 2k epoxy primer seems to be a good option (Lechler?)

I've never compressor sprayed and I don't have any spraying / painting kit / masks, I don't intend to spray the car myself as I will just make an arse of it, so if I had to buy spraying kit I'd only use it for this 'protection' and the prep primer / filler stage, but I do have a compressor.

Because of how slowly I work I could need to spray say the inside area of the boot now and the underside of the boot could be another month before I'm ready so I really can't be masking and sealing the whole of the garage off each time I have to spray another small area (If that's necessary)

Initially I just thought I'd rattle can primer and then spray some random coat of rattle can paint over it in order to try and temporarily seal it, but bearing in mind at some point I'll need to filler / filler prime these areas at a later date I'm not so sure this is a good plan as far as any potential paint / filler reactions?

I've seen Eastwood (Frost) do a 2K / 2 part epoxy rattle cans but at £25 for a smallish can which has to be used inside 12 hours after it's been 'activated' I'm not sure it's a great option?

So just after some advice on how best to proceed

Cheers

I used rustbuster 121 epoxy underneath and the 421 on top and inside. Its not the cheapest but i had seen good reviews in practical classics. Its very thick so does require thinning quite a lot to spray it.

I used a 3m full face mask for spraying, ideally i think you would want an air fed mask but i was too tight to buy one.

I have bought a big tin of jotun mastic for subframes and suspension as its cheaper but not used it yet so can't comment. Its used for painting hulls and anything else submerged in water so should cope well on a car.

If you overcoat within about 2 weeks (depending on temperature) theres no need to key the surface so could just go straight on with high build ready for final prep.

I think most epoxy primers are much the same so you should be fine using any brand really.

For truely bare metal I personally use 2K etch primer first. It's not high build like a normal primer (which goes on after the etch but only when I'm ready) but keys to bare metal much better.
But I do have an air fed mask, a suitably large compressor and its air intake is ducted from outside.

One thing I would add, about 30 years ago we had a house with the garage built in (on three sides and with bedrooms above) and if I sprayed anything other than a tiny amount of paint the whole house would stink of thinners for days.
That was despite the garage supposedly being fire segregated from all the living areas.
Only cellulose back then, no isocyanates, but something to bear in mind.

Schrödinger's cat - so which one am I ???

I used upol acid etch from a can on mine.

Unforyunately I don't know what it's like holding back the rust as I don't have that issue. Some bits were in primer for a good year though.

2k high build went on that than 2k top.

Thanks for the responses

I think I'll have to carry on as I am, I have used UPOL acid etch primer too, it states that it provides corrosion protection as well as improved adhesion.

I have the problem already of garage smells coming in to the house, be it grinding or a little spray rattle cannage.. Makes me very popular :)

Cheers

Most "normal" rattle can primers are, like most other primers,porous and absorb moisture from the air.This will spoil the final finish.
A thin coat of rattle can gloss will seal it though, and can be overpainted with the usual high build primer eventually.

As Rod says, for best adhesion use an etch primer.

cosserick is the man to speak to, fairly certain he's a painter by trade

Evening all , epoxy is the way to go if you can ! But my got make sure you have a good mask / ventilation , but that's said with any 2k product.
The bonus is it has better rust inhibitors than normal etch primer and it has a reasonable build to it and it can usually be painted straight over where's an etch needs a primer before colour ! Aerosol is ok for spot priming or break through bits but isn't hasn't the durability that a proper 2k has . Yes you could aerosol bits to try keep rust at bay but I'd consider stripping it back off when you come to paint it properly as I wouldn't want to relay on that as my base layer holding all the other expensive paint on the car etc !

Rick

Roller it.

This panel was rollered. That is not flatted and compounded either.

Dont think of spraying 2k in your home garage. Especially given its attached to the house. Its very sketchy stuff.

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