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[clockworks]

I'm finishing an Aeronaut Diva, which has a sheeted over frame hull. The bottom of the hull is normal birch ply, the sides of the hull are mahogany-faced ply.


I used sanding sealer over the whole hull, then several coats of Ronseal Yacht Varnish on the upper hull.


I masked off the mahogany areas, leaving the lower 5mm or so exposed, and sprayed on a couple of thin coats of Halfords white primer. The exposed varnished areas have wrinkled badly, so I'll have to sand back the hull and start again.


This is the first time that I've tried to build a boat with a part natural wood/part painted hull, so I've not tried painting over varnish before.


What paint and varnish would you recommend that I can use together without causing problems? Needs to be something that I can brush or spray from a can, and that I can actually buy during lockdown.

[DaveM]

Before Mr Jones leaps in with his advice/critique, I'd be very wary of using a solvent-based primer or paint over an oil-based varnish. Halfords white primer is rubbish anyway - it never seems to set hard. I'd suggest an enamel matt coat for the white primer/base and a similar gloss for the top coats. You can get Humbrol from most model outlets by mail-order, even in these strange times.
DaveM

[coch y bonddu]

Mr Milbs is 100% correct the varnish is enamel the aerosol is acrylic  hence chemical reaction...as for the white primer dont even get me started best place for that is the bin.




Dave

[Colin Bishop]

One further minor point. Yacht varnish is intended to be a final decorative/protective coat and is slightly flexible to acommodate thermal movement on full size boats so as well as being affected by solvents from spray cans it doesn't really like anything else on top so you are quite right to sand back to the hull in ny event. Don't worry too much, most of us have been in a similar situation!

Colin

[clockworks]

Humbrol primer (or matt white) and Humbrol gloss white aerosols over the Ronseal varnish should be OK then?
I'd rather not sand the whole hull back to bare wood, as the deck and coamings are all glued in place.


I agree about the Halfords white primer being a bit rubbish. Very odd, since all their other aerosols seem to work so well.
What is the best primer to use under the lighter Halfords top coats?

[clockworks]

It looks like Humbrol have stopped making enamel aerosols. Checking their web store, the only enamel aerosols listed are clear - no colours at all.


Are Tamiya aerosols less aggressive than Halfords primer?

[Colin Bishop]

Anything out of a spray can is liable to react with yacht varnish as it includes a pressurised solvent. You probably need to brush paint with enamel. Most of the house paint you buy in DiY stores is pretty useless as nearly all of it is waterbased. You really need a proper yacht enamel such as Toplac which is designed to be used on full size boats.

https://www.marinesuperstore.com/paint-cleaners-care/paints/international-toplac-enamel-topside-paint?gclid=Cj0KCQjw4dr0BRCxARIsAKUNjWQ5nEjMM94-glorkzFZfbIFye3j-TY5IELFIPBm4leT1ELgbOO0KUwaApj3EALw_wcB

Data here:

https://www.international-yachtpaint.com/en/gb/boat-paint-products/topcoat-finishes/toplac

I used the snow white on my Fairey Huntsman kit.

Yes, it is expensive but  you can also use it for other things such as on the outside of your house where it outlasts anything you can buy in th DiY stores. It brushes out very well to give a lovely finish.

Colin

[clockworks]

Thanks for the link. I've just ordered a can of Toplac.


Nice looking boat. I've got a Huntsman 31 to build next.

[roycv]

My problem with varnish is that you have to buy larger quantities than you need at the time and it all seems OK until the last 20 % which dries off in the bottom of the tin. 

Next time as soon as I get to halfway down I shall decant the varnish into a smaller receptacle to reduce the amount of air in the tin.
regards
Roy

[Colin Bishop]

A while back I had a builder in to do some repairs to my car port. He initially jibbed when I said I wanted him to use the Toplac to paint the timber structure which I would provide instead of his usual 'trade' paint. Two hours later he simply couldn't praise it more highly, he thought it was wonderful!

Colin

[SteamboatPhil]

To get the  finish I have on my boats I always warm a small amount of the paint (having thinned it down) brush on and walk away for a day or so, never try and brush over already brushed on paint, it will go wrong...spray painting is a mystery to me although a certain person has tried to explain it to me for many years....mainly in welsh I thought (sorry Stav could not resist ) 

[ChrisF]

I was planning on spraying my models but fancy hand  painting them. What sort of finish can be achieved as I don't want to see brush strokes unless minor.

Chris

[clockworks]

Got my tin of Toplac, put the first coat on yesterday.

What can I use to thin it down a little - it's quite thick, and hard to keep a "wet edge".
Instructions on the can say to use Toplac thinner. but I obviously don't have any of that, and would rather not wait another week to get some mail order if there's something else that will do the job.  White spirit worked OK for cleaning the brush.

[Colin Bishop]

I've never needed to thin it myself, might be worth warming it slightly. If you do need to thin it then white spirit should be fine but best to try it out on a test piece first.

Colin

[clockworks]

I think you might be right that it doesn't need thinning. I just put the second coat on, and it flowed a lot better. Maybe I put the first coat on a bit too thinly?