To Paint or not to paint?

[pcatterall]

The white hull of our 1974 Neptunian always responds to an annual T cut and a few coats of wax and looks good for at least a year even now we are in the med.
The decks scrub up well and get the masonry paint treatment now and again.
the upper works are a different story! The sides of the coachroof and dog house were a light blue 'self coloured' gel coat which has mottled and does not respond even to wet and dry.
T cut does give it a shine but even with several coats of wax it soon goes dull.
Question is should we paint the upper works and if so with what?
I am concerned that paint will easily mark and scratch particularly in the places where crews feet may slide around.
I understand that some paints are especially tough ( 2 pack stuff?) and seek your views please.

 

[SailSouth]

Think long hand hard about painting, it's a one-way street but eventually necessary for all boats unless you vinyl-wrap or re-gel.

I think I would, given good conditions and the time to prep it properly, do a 2-pack job with International Perfection. I have roll-and tipped perfection to a very good finish and it has lasted well. A good thick coat can also be cut back to refinish.

 

[Tranona]

Painting a coachroof is probably the most difficult painting job on the boat because of all the fittings, holes, changes in surface direction and small areas - even worse if you want to do the decks as well - which makes sense as one of thee worst bits is the junction between the deck and coachroof. The best way is to strip everything off, windows out mask up and spray with a 2 part paint such as Awlgrip. However this will cost probably as much as the boat is worth.

For a DIY job look no further than the sponsor of this forum. PBO publish an excellent book on refurbishing MABs derived from their series a couple of years ago refurbishing a 21'. There is an excellent section on painting discussing the pros and cons of the main options and then how to go about it. Yes a 2 pot polyurethane is arguably the best, but comes at a cost and requires a higher skill level plus better environmental conditions to do successfully. A modern one pot such as Toplac will give good results for lower cost and less skill, but still good shine and reasonable durability. However as with all paint jobs the real work is in the preparation.

 

[Pauly]

Before opting for a paint job it might be worth considering a machine compound and polish if you haven't already done so.

 

[PaulRainbow]

<snip>However as with all paint jobs the real work is in the preparation.

I agree. So, it makes sense (IMO) to consider re-doing the gelcoat. This can be done DIY and wouldn't cost a fortune.

 

[pcatterall]

Before opting for a paint job it might be worth considering a machine compound and polish if you haven't already done so.

We tried some areas starting with 240 grit wet and dry and working up in stages to 2000 grit. only partly successful and although the gel coat is thick there is a prospect of removing it all!!

 

[Pauly]

What do you do after 2000 grit? At that point I get the machine and G10 liquid out and go over a couple of times, keeping the working area wet with water from a hand spray. This shouldn't involve any further material removal but will get rid of working marks from the wet and dry and leave you with a pretty shiney surface that just remains to be polished.

 

[jwilson]

I have painted a not that big GRP cockpit well (the only bit of the boat not covered in teak) and it was a sod of a job to get good results. Which I mostly did in the end, with Awlgrip over lots of prep, filling nicks and scratches. Once done it improved the boat, and lasted well, but I'd never start that job again. All the bends, curves, fittings make the job far worse than just painting hull sides.

I have never re-gelcoated, but watched it being done, and it is not a trivial job even on nice flattish easy to work areas such as hull sides. On a coachroof an/or cockpit wih lots of angles it would be ten times more difficult.

 

[pcatterall]

What do you do after 2000 grit? At that point I get the machine and G10 liquid out and go over a couple of times, keeping the working area wet with water from a hand spray. This shouldn't involve any further material removal but will get rid of working marks from the wet and dry and leave you with a pretty shiney surface that just remains to be polished.

T cut and then wax.

 

[Pauly]

I think you'd get much better results with a rotary polisher. Lots of video guides available on the 'net. I've done my last 3 boats like this, all old and neglected, and only ever had to do it once. Wash and polish at lift out is the only other treatment they've needed.

 

[yerffoeg]

There is a good case for externally painting old fibreglass boats. When the gelcoat is over 30 years old it is not easy to get a good finish by polishing etc. I painted the topsides and hull of my 1973 boat with Sandtex 10 year exterior gloss from B & Q (Ha!) with pretty good results. Surface preparation is of course important, and masking takes ages. I used a foam roller and foam brush, and diluted the paint 10%. After 6 years I am still pleased with the result, but accept that external paint is sacrificial and will probably need to do it again at some point. If you get a scratch it is easy to touch up. For further advice check out one of Don Casey's superbly written articles/ books on the subject.

 

[Boathook]

I did my coach roof with toplac and mixed it 50/50 with the flattener (removes the gloss shine) so that it didn't show every little defect. That was about 6 or 7 years ago and it is getting to the stage for another coat. Spent a lot more time removing fittings, sanding and then masking than actual painting.