Spraying steel with polyester

[Dresca]

Hi

I have a number of hard steel moulds that I would like to surface with polyester. I have some high build primers & finishing coats. Anyone have any experience of coating steel this way? What kind of durability did the coating have?

Many thanks
Dresca

[wannasail53]

Dresca, You might find this site interesting, I am about to use the product for rust prevention, do not know if it will fill your needs but the product seems to be a great advance for coating and waterproofing steel, wood and glass. http://www.sanitred.com/

[ondarvr]

Polyester won't work well, it may stick long enough for you get it sprayed, sanded and buffed, but propably wouldn't hold up through the first part you make.

[Wynand N]

Interfill 830 - made by International yachtpaints.

This is what I use on my steel hulls to cover, repair and smooth plate. It is a two part epoxy, works and smooth easily and takes paints well.

[Dresca]

Hi again

Thanks for the replies. We got in trouble with local police over emissions! So I've been hiding in UK until things quietened down slightly! Back now, so picking up my emails.

Just to let you know what I did. I rough sanded the steel with a 40 grit, just hard scratched it by hand. I put in radius with a 'ball on stick' type tool, with an easy sand polyester car filler where needed. Then HVLP sprayed a thick coat of this easy sand polyester primer. Then finished this with a hard tooling topcoat. Took this all back to about a 1200grit & polished.

Its lasted for about 20 pulls I guess so far. The only problems were the weak car body filler which line-cracked under the pull pressure. I used no semi-perms and only wax. Seems to be a good mould. The steel structure goes on and on, but if I doesn't make a high number of pulls then I'll try your Epoxy primer.

Thanks for replies again :)

[ondarvr]

you did well, typically polyester gel coats won't bond all that well to steal and when stressed they tend to pop off.