Painting Problems

[Matt C BeechParticipant @mattcbeech]

I was putting on a top coat today (Enamel) on metal which has been etch-primed and undercoated (fully dried)

And as I sprayed the paint it all went very crinkly:

Any tips?

Matt

[Matt C BeechParticipant @mattcbeech]

[Neil WyattModerator @neilwyatt]

That looks like nitrocellulose paint that's attached an acrylic primer underneath.

Do it again in black for that authentic 'Japanned' look.

Neil

[Matt C BeechParticipant @mattcbeech]

Neil, thanks for your thoughts. I'm not sure that's the whole of it though. The paints I used are all from the same set and compatible (Tekaloids)

1) Tractol 729 Single Pack Etch Primer (http://www.smithandallan.com/prodpage.aspx?id=1445)

2) Tractol 816 Single Pack Undercoat Dark Grey (http://www.smithandallan.com/prodpage.aspx?id=2567)

3) Tractol 329 Single Pack Machinery Enamel (http://www.smithandallan.com/prodpage.aspx?id=1568)

They are all sold as compatible with each other.

The effect isn't universal, and may be a result of me over-spraying…

Matt

[Phil WhitleyParticipant @philwhitley94135]

Check your paint instructions, you also get this type of partial crinkling when the solvent in the latest coat softens the paint below it in some areas. You will see on some paints "overcoat within 24 hours or after 2 weeks". this is to ensure that the underneath coat has either not cured at all, or has fully cured and will not "move" when the thinner in the top coat hits it.

Phil

[stan pearson 1Participant @stanpearson1]

Hi Matt

I have always used self etch left for 48hrs and sprayed with cellulose top coat on all my model loco`s, I think you didn`t leave the etch long enough to dry and the activator has reacted with the enamel or the etch coat was too thick it should be one thin coat mixed 50-50 with the activator, and spray a thin top coat first and when the hairs on the back of your hand stick to it put on a second wet coat.

Regards

Stan

[Cyril BonnettParticipant @cyrilbonnett24790]

Does this help!

**LINK**

Cyril

[old AlParticipant @oldal]

what do you mean, fully dried.. How long was your drying time. I was tolsd by my paint supplier 1/4 hour for small parts, but that always causes problems, so I leave it all day now.

Also, are you sure you didn't use gunwash/cellulose thinners in place of the correct thinners. You wouldn't be the first, or last.

[Matt C BeechParticipant @mattcbeech]

Thanks Cyril,

I think its probably a bit thick as you suggest.

I’ve checked the instructions and they suggest overcoating after 6 to 15 hours. I left 2-3 weeks between etch primer and undercoat and the same between undercoat and topcoat.

I’m using aerosols so probably the lack of control laid it on a bit thick.

Thanks,

Matt

[DustyParticipant @dusty]

Matt

Looking at your photo it appears to be a chemical reaction rather than the application, if it were to thick I would expect to see runs or sags in the paint, I can see no evidence of that. It points to the finishing coat reacting to what is underneath. You say you left it for a couple of weeks before recoating, could it have been contaminated during this period? I always go over the item with pre paint solvent (obtainable from your local car re-finishing shop) just before painting. The other thing is do not leave drying parts in freezing workshops, small parts can be hidden around the house away from prying eyes. Larger parts need negotiation.

[Rick Kirkland 1Participant @rickkirkland1]

Matt, I'm with Phil Whitley on this one based on my time in vehicle refinishing if you don't use the paint and apply it as per manufacturers instructions the thinner or solvent in the paint will affect the coat below. We used to get round this by using a sealer coat which would form a barrier between the coats but still provide adhesion. Sealer primers and surfacers were also used over hygroscopic etch primers if they needed to be left for any length of time due to the etch primer causing rust on ferrous substrates when they absorbed atmospheric moisture. Obviously dont apply sealers untill the paint is ready to accept it.

Rick

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