Painting problem

[Dave nichollsParticipant @davenicholls]

Hi everyone its monday ,

Can anyone help me, on the lower half of my boat hull i have airbrushed a matt rust colour enamel paint made by Phoenix precision. The rest of the hull is painted with aerosol paint for cars. What i intended to do was use clear lacqu

er to finish the job, having sprayed the clear lacquer on a test piece of the rust colour, this revealed blistering of paint. Do i need to purchase lacquer suitable for enamel paint and only spray the rust colour. HELP.

Regards, Dave

[Dave nichollsParticipant @davenicholls]

[ashley needhamParticipant @ashleyneedham69188]

Dave, a minefeild , this… Its is a case of buying different laquers and trying on scraps of paint samples…

However I have found "household" acrylic varnish does not appear to affect and paint finish I have used so far. You may be able to spray it. Blackfriars or Rustins, from homebase etc. Although marked as for internal use, it is has not been affected (so far) by a few hours in the drink.

Do you need to apply varnish on this? I try not to as it makes touching up later on very difficult.

Ashley

[Colin BishopModerator @colinbishop34627]

Matt polyurethane varnish (NOT the quick drying type) goes on over just about everything without problems and you can thin it with white spirit for spraying. I assume that is what Ashely is referring to.

The interior and exterior varieties are equally durable but the latter has UV filters in it which give it a slightly yellowish tint.

As always, do a test piece first.

Your problem is caused by the solvent in the can reacting with the enamel. Wherever possible it is best to stick with paint from a single manufacturer as different brand of acrylic spray cans are frequently incompatible with one another due to differences in the solvent.

Colin

[Dave nichollsParticipant @davenicholls]

Thanks Ashley & Colin for information on my paint problem, i will stick to aerosols in future as i have never had a problem before. Trying to save money has caused me more problems than sticking to a system that has worked for me on three other boats.

Regards,

Dave

[Armando LoniParticipant @armandoloni78860]

Dave – the rule of thumb is that oil-based paints (Humbrol, enamels, etc) can be used on top of acrylics (automotive/aerosol spray paint) but not the other way around…… unless you want a weathered finish!

[ashley needhamParticipant @ashleyneedham69188]

I use the quick drying variety of varnish and have had no probs.. Is perfectly waterproof for several hours boating and does not yellow..?

I have used car spray only on my large warships, they are grey all over so it is easy to get a nice flat finish. I didnt fancy trying to get a nice even, flat run and hair free surface on the carrier with ordinary paint.. but 15 mins on a hot day and the job was done!

Ashley

[Colin BishopModerator @colinbishop34627]

Ashley, With the quick drying variety I think it very much depends on what you put it over. I have had quite specific problems with it in that it can sometimes bloom in water even when supposed to be fully dry. The other issue I have had is that it appears to form a film over the underlying surface with limited adhesion so that if the film is broken, by an impact for example, water gets under it and it begins to peel away. That is why I always use the polyurethane variety which has a proper solvent and is not water based. And it's a lot tougher too.

Colin

[ashley needhamParticipant @ashleyneedham69188]

I must say that I only ever varnish matt surfaces, to seal them as they scuff and pick up marks very easily. The matt varnish doesnt tend to give a good matt.more of a dull satin, but thats ok for me usually.

I have not experienced the peeling..perhaps I have been lucky in my choice of initial paint.

Ashley

[BRYAN ASTONParticipant @bryanaston57723]

Greetings all

One of my older boats needs a fresh coat of paint ,due to various details and parts already attached to the hull I cannot easily spray the hull without covering the aforementioned parts etc. masking is not an option.

I am sure some of you have had a similar problem, I therefore ,would welcome any tips regarding what paint to use,what brush to use and any other suggestions to avoid the dreaded brush marks

Yours in anticipation

Bryan

[Malcolm FraryParticipant @malcolmfrary95515]

Any cellulose based paint will act as a good paint stripper for any oil based paint if it is applied wet enough for the solvent to still be active. The solvent in wet oil base paint is not active enough to have an effect on dried cellulose paint. The word "solvent" is a clue – it indicates a fluid that dissolves other substances. Different solvents dissolve different substances. Acetone (the usual one in cellulose) will attack many plastics (don't paint your plastic kit with it) and the residue that oil based paints leave when dry.

The issue is now confused because modern acrylics are a category of their own (water plus alcohol plus summat), and anyway, paint manufacturers are reluctant to tell anybody what is actually in there, so a lacquer that is perfectly good over a selection of automotive colourings, acrylic or cellulose, might, or might not, react with enamel. Depending on the enamel, and what is in the lacquer and if spraying, just how dry it is when it lands on the painted surface.

To avoid brush marks, go to a proper art supplier and get a set of good soft brushes. I like the flat type for large area and round for smaller details. And clean them after use. Stiff bristled brushes are good for artists artistically putting texture into their efforts. Texture is the one thing that we really don't want, so soft bristles.

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