Spraying my boat

Automotive fillers/repair kits come in a variety of polyester based blends. As a matter of fact most of their products are now rated for marine (boat repair) use and labelled as automotive/boat. Those containing glass fibers branded as "Hair" come in a selection of light-medium and heavy blends are rated as such. While I certainly don't recommend them for major hull repairs they are certainly ok for smaller holes and gouges. Again preporation is the key to any repair regardless of what is used. The photos below show the product that is rated for marine use, but in this case I am using it as a convenient off the shelf filler/bedding compound around my floor timber's waterways and a base for my epoxy laminated white oak floors.

 

Hi iv used the filler and I'm going to use the high build car primer from halfords what do you all think thanks for everyone who's replying

 

Just curious -- what colour is the primer? Is it a special purpose primer? I.E. to be used with only a certain type of paint and have you chosen your boats new colour. Just asking as a light colour primer along with a light colour paint could result in a two coat finish verses three to cover a dark primer. Keep in mind that light colours hide alot of imperfections. Also keep in mind it is important that the primer and the paint be compatable. If you're not sure check with the primers manufacturer or supplier. Otherwise a few pointers that you might be well aware of but I'll mention them anyhow.Final hand sand your hull before and after applying the primer using 400 to 600. It is very important the hull be well sanded before applying primer to remove any wax and give the primer a good bonding surface. Next blow off the dust before and after priming,at 100psi or so with good cross ventilation, wipe her down with a clean lint free cloth dampened with a little paint thinner, slightly water down the floor water to control stirring up dust and lay on the paint. Good luck, be patient, and have fun.

 

I wouldn't recommend a 400 - 600 grit hand (or machine) sanding before primer. This is way too smooth for a high build, high solids primer. You need "tooth" for these types of primers to bond well. 100 - 120 is perfect, though most like to go up a bit higher, say 180, with 220 being as high as I'd risk a high build primer. Now this isn't true of tie coats or regular primers, where you'll want a 220 - 280 grit surface, to minimize sanding scratches. A high build primer will easily fill 100 - 120 scratches and has plenty of physical area to "key" to.

I also disagree about blowing off the sanding dust. The only time I will do this is well away from the painting area. My final sands are often wet, so blowing off dust is moot. In other words, if you blow off dust, it's just going to settle back down on the boat (and everything else), even with ventilation, so if you use air, do so outside, then push the boat into the paint area, where you can tack it down, in a clean environment.

I agree on the wet floor trick, if your conditions are less than ideal. If you have a clean area, this isn't necessary or desirable for some paints (some don't like moisture). Flow through or down draft ventilation is desirable, unless using a water borne system, where you'll prefer an oscillating fan (more then one) type of air flow.

I also agree that light colored primer, with light color top coats can make the job easier, with fewer coats too. If you can, match or pre-tint the last coat of primer, so the top coat goes over a uniform and "sympathetic" color, you're ahead of the curve.

 

Yes of course "high build" missed that point of info. Seems i've also been oversanding a little on regular primers, however I've had no problems with paint adhering to the smoother finishes. Don't have the patience for wet sanding then again whenever possible I always tried farming out the whole finishing stage to guys that are far better at it than me. Quite similar to taping, plastering, painting inside and roofing outside, in what was my main money making field of carpentry. Dam booring work is best pawned off to others with more patience. However I find as I grow older and a little less financially stressed I am learning to overcome this by intermixing the booring with the interesting challenging work by a ratio of approx. 25 to 75 %. At my present progress rate (fighting to get time on it)on my build I should be an expert finisher at 100yrs. old

 

Thanks for replying everyone Iv changed my mind again lol I'm going to get a 1lt pot of light grey high build primer (cellulous paint) then I'm planning on useing a light blue to paint the outside and a very dark on the inside but I must stress as I'm very close to painting ARE CAR PAINTS OK TO UES

Thanks everyone
Ps ill upload a pic for you all

 

Cellulose paint is what we call lacquer here in the colonies. Technically they're different in regard to the chemistry (plasticizers mostly). This is the easiest paint to use for the DIY'rer, though it can be fiddly over some substrates. I would suspect a cellulose primer would be better then top coats in this regard. I haven't shot any of this stuff in years and am glad for it.

Cellulose doesn't leave you with a wonderful finish, it has to be buffed up regularly, unlike the modern acrylic urethanes and LPU's, which hold their gloss very well. Make sure you have a good chemical mask. You shouldn't be able to smell any paint while applying it.

Again, yes, you can use automotive paint, so long as you don't leave the boat in the water very long (more then 24 hours). You can probably get away with longer, but you're risking lifting the paint film after 24. This isn't especially true of the LPU's, which seem to have a much better substrate grip and have tolerated much longer immersion times, without issue. I wouldn't tempt fate with a lacquer. I thought they banned the lacquers/cellulose paints in the UK too.