spraying a boat

Captain Coochie

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I need to get my boat lifted for a well deserved bottom scrub , it also could do with a lick of paint on the hull and topsides as its a 1972 cruiser and well past the pretty gel coat finish .
I have a compressor and spray gun that i use to finish my carpentry projects ( not many as im no pro at spraying ) I just wondered if anyone had sprayed a boat and what paint ,thinners etc they used ?
 
I have used 2-pack acryllic, with a coat of etch-primer on first, this gives very good adhesion to the gel coat. The etch-primer is the same as used on galvanised or aluminium car panels. 2-pack is easy to use, but wear an organic vapour mask at all times.
Peter
 
I need to spray our club boats (4) at least every couple of years because of members damaging them.
Firstly to answer your main questions, yes you can re-spray and get reasonable results so long as you know your way round a spray gun and secondly, I use Toplac because in can be thinned with white spirit and is less dangerous than 2 pot stuff and you can get the same results.
BUT as with any painting/spraying the end result will only reflect the amount of work you put into the preparation. Spraying has a knack of showing every little knock and ding in the surface.
I use P38 filler rubbed back and then I spray a light base grey filler/undercoat which shows up all those imperfections - sort them - then when your happy with the surface I spray 2 good coats of grey again, rub it down with 600 wet and dry then go with the first top coat thinned @ 50%, next coat @ 65% then the final coats @ 80%, rubbing down between coats with 1200 wet and dry and soap on the W & D.

I have also tried laying down the top coats using a paint pad to apply the paint and a clean dry brush to "lay" it off, with just as good a result - but you must brush the lay off horizontally.

Peter. /forums/images/graemlins/smile.gif
 
Most of the time in a repaint is in the preparation - removing/replacing hardware, filling, sanding, etc. That is all the non skilled stuff that mostly anyone can do. Much of the cost is in that and in the cost of the paint itself.

The spraying the paint on is the bit that is real easy to mess up but is the part of the job that only takes a very short time (I have seen a single top coat put on the topsides of a 75 foot boat whose build I have been managing within a lunchtime while the rest of the yard were eating) so is cheap compared to the rest of the job - so consider getting a friendly professional to lay the paint on (even if just the top coats) while you do the preparation.

Despite claims to the contrary, if you want a long lived job there is only one paint type to use - that is a two pot polyurethane. It will give you at least 10 years life for difficult colours such as red or blue and at least 15 for white.

Some on these forums claim that you cannot repair/colour match polyurethane - if anyone tells you that, it is not so - have a chat to a good boat painting company about it. I have seen it done frequently, including on my own boat. As always, White is the easiest to match because of the lack of fading - and unlike the car and house paint manufacturers the reputable marine polyurethane companies stick to their colour charts for many years. Faded colours (ie not a stock white) will always be a problem for touch ups in any paint as there are no edges to paint to to create a break from the surrounding existing paint (such as the panels on a car) and the harsh environment.

John
 
A couple of points I would add,since they are not mentioned in any of the threads.....
Open up any cracks in the gelcoat with a hacksaw blade and then fill them-the paint will not fill them but reveal them more..

You need a far larger compressor than you might think,rent or borrow but it has to keep up with you as you spray otherwise you will get a marginal spray pattern and a disappointing finish.

For masking off use paper and do not be tempted to use plastic sheeting!Paint does not adhere to the plastic thus what is oversprayed on the primer coats gets dislodged and splattered back on to the finish coat!

Oh and check with the paint maker regarding using some accelerator in the top coat probably in the Uk.You want it well and truly cured by the time dew settles.I learnt that one the hard way ,had to respray my mast cos it went dull(aluminium is very prone to condensation as you prob know)
It will look great.
 
I am an enthusiastic have a go at anything type and recently sprayed my boat using two pack etch primer and a good quality two pack topcoat. I was lucky enough to have the use of a workshop with a large compressor and after applying the primer which was later flatted. I applied about 5 coats of top coat which went on beautifully is really shiny and hard as nails. The job was a lot easier than anticipated and the results amazing.
 
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