Model Boat Mayhem
Technical, Techniques, Hints, and Tips => Painting, Finishing and Care. => Topic started by: AlanP on January 28, 2010, 05:14:35 pm
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Ill start from the beginning. Hull was washed off, wet and dry fine grade was used all over the hull, the whole hull was given two coats of primer, masked off and red oxide sprayed for the bottom OK, masked off and the green paint sprayed on OK, masked off for the white paint at the top of the hull and after spraying quite a few areas of pin prick holes appeared, used wet and dry on these areas and resprayed, the pinprick holes came back <:(
Any thoughts would be appreciated
Alan
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Alan,
Thats rough, it sounds like there are spots of grease or oil on the hull, could have come from fingers or something?
Anyway, after wet and dry (including a drop of fairy liquid), wash with warm soapy water, rinse in warm clear water, allow to dry properly without touching the area to be painted, then wipe down with a lint free cloth and white spirit and allow to dry off before painting.
Hope this helps.
Ian
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In addition to what Ian has pointed out, you may want to think about some silicone based product having come in contact with the hull. No amount of water cleaning will remove it. You'll need a proper silicone removing fluid. This is available at auto parts supply houses.
John
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In addition to what Ian has pointed out, you may want to think about some silicone based product having come in contact with the hull. No amount of water cleaning will remove it. You'll need a proper silicone removing fluid. This is available at auto parts supply houses.
John
automotive Panel wipe is a good bet gets just about anything off
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Hi Alan,
Did these holes appear whilst the paint was still wet, or after it had 'flashed off '? If it was still wet, I would agree with Ian & say its grease or some form of silicon causing the problem. Are you using spray cans or an airbrush/ spray gun to apply the paint? if you are using the latter, it could also be caused by water or oil in the air supply.
i agree with Ian suggestions to rectify this, although I would use a clean, lint free cloth to buff the white spirit off of the hull before it dries, as some times the spirit can just spread the grease around the hull rather than remove it. Also i would prefer to use spirit wipe/panel cleaner/pre-paint (its all the same thing just different names) as used by professional car painters. it usually comes in 5 litre tins, but a trip to a local painters with a tin & a donation to the tea fund usually works, as u don't need much. One word of warning if you use this stuff, is to try it on a small piece of the hull first as it can sometimes wet the paint back up & cause more trouble than u already have. It really depends on the paint you have used, but should be fine with halfords type spray cans.
If the holes appeared after the paint had flashed off, well that could be a whole different story & I would need to know more information before I could give any advice on rectification.
Hope this helps, cheers Glenn
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Thanks very much for the replies.
I will give it tomorrow for the paint to harden, then I will wet & dry it back to the FG, wash it, wipe it, buff it, and kiss it before putting on some primer to see if they come back :-))
Alan
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Just make sure you take off the lippy before you kiss it :-))
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Well I did what I said I would do apart from kissing it, some dissapeared but about half a dozen remained. Took it back to the fibreglass again and got a magnifying glass on it, it would appear that there is something embedded in the fibreglass hull, got a 2mm drill and countersunk all of the spots, filled with liquid filler, sanded, undercoated and it looks like they have gone. A couple of days for it to dry and then I will put the finishing coat on. If they reappear I will paint some rust marks from them :}
Alan
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Good news, sounds like the mould had a few dirty spots on it.
Ian