Paint or Re-Gelcoat ?

[Yealm]

The top sides on my 40y boat are getting tired, with some cracking, pinpricks and white oxidation (brown hull). I think it’s the original gelcoat, though not totally sure, may have been painted in places.

I was thinking of re-coating the top sides and changing colour to white.

What are the pros and cons of paint and gelcoat respectively?

Many thanks

 

[pcatterall]

If you don't mind the brown colour and you can check any painted areas then a really good polish to remove the oxidisation might bring a new lease of life to the old lady.

gelcoat would be a much longer lasting solution but at a price!

 

[doug748]

I had a good quote for re-gelcoating a couple of years ago but, for various reasons, have not gone for it yet. Friends of mine had a GK 29 done and I saw it 5 years later, still in excellent condition, decks as well.

Anyway, Spencer Fleet at Yacht Haven Quay Plymouth would be worth talking to.
If/when mine is done it will be in white.

Let us know how you get on.

 

[Yealm]

Thanks - yes my friend recommended him today !

I had a good quote for re-gelcoating a couple of years ago but, for various reasons, have not gone for it yet. Friends of mine had a GK 29 done and I saw it 5 years later, still in excellent condition, decks as well.

Anyway, Spencer Fleet at Yacht Haven Quay Plymouth would be worth talking to.
If/when mine is done it will be in white.

Let us know how you get on.

 

[caerolusmagnus]

I am in process of re-painting a hull, previously painted. Hull was scuffed and gouged in places. Am also raising the LWL and new Boot-Top being applied.

I will send a PDF of progress with comments and photos so far to anyone who wishes.

rivalsapphire@gmail.com

 

[pcatterall]

Pros and cons gel coat versus paint. cant offer experience but am considering similar issue. I think that even the best paint is more liable to suffer scratches and look tatty sooner than well applied gel coat. I understand that gel coating will be significantly more expensive. perhaps folk would like to offer their knowledge and expertise?

 

[MM5AHO]

I am in process of re-painting a hull, previously painted. Hull was scuffed and gouged in places. Am also raising the LWL and new Boot-Top being applied.

I will send a PDF of progress with comments and photos so far to anyone who wishes.

rivalsapphire@gmail.com

ditto on R32. Awlgrip awl over

 

[caerolusmagnus]

I agree that gel-coat may be less prone to scratches etc.
Having inherited a prior-painted boat, I am willing to continue with paint.
I will be able to re-touch the Toplac alkyd enamel given my ongoing and accumulating experience.

Just to add, this is in preference to an Awlgrip/Awlcraft paint. I had such on Contessa 32 and Ohlson 38.
Expensive and beautiful to look at. However, When the Awlcraft/Awlcraft scratches it is much more difficult to retouch. The Awlcraft is the softer verion of Awlgrip and more easily buffed in early stages of application life.
Also Awlgrip/Awlcraft will take any amount of splashing but will bubble off the hull if continually immersed.

 

[Yealm]

other than price, are there any downsides to redo Gelcoat?

Is it technically harder to get right ?
And I guess will need to remove the toerail- god knows how you do that and then replace it, on an old boat..!

I agree that gel-coat may be less prone to scratches etc.
Having inherited a prior-painted boat, I am willing to continue with paint.
I will be able to re-touch the Toplac alkyd enamel given my ongoing and accumulating experience.

Just to add, this is in preference to an Awlgrip/Awlcraft paint. I had such on Contessa 32 and Ohlson 38.
Expensive and beautiful to look at. However, When the Awlcraft/Awlcraft scratches it is much more difficult to retouch. The Awlcraft is the softer verion of Awlgrip and more easily buffed in early stages of application life.
Also Awlgrip/Awlcraft will take any amount of splashing but will bubble off the hull if continually immersed.

 

[William_H]

I am really confused about this idea of redoing gel coat. Will professionals do it? Is it only because owners want to replace original finish? AFAIK it would be bad thing to do. Gel coat is polyester resin with a pigment for colour. It is painted on to the mould as a first layer. It can be thick or multi layered. It is then covered with the glass and resin of the substrate but the next layer is applied before the gel coat has gone hard. This means that you get a chemical bond of gel coat to the substrate. That bond is very good.
Now if gel coat is applied to an old hull it would have to rely on mechanical bonding ie the gel coat runs into uneveness of the hull to grip. Now polyester resin is not so good at mechanical bond to anything because it does shrink and does not bind well. Hence we always use epoxy as a much better bonding resin than polyester. Mind many people do use polyester resin to bond to old polyester with some success but it is no the best. Now because epoxy deteriorates in the sun it must be itself painted. Polyurethane is used as a paint and is good in sun and bonds well. So IMHO paint the hull if you have given up on polishing and trying to touch up nicks. Either 2 pack polyurethane or one of the modern robust one pack paints. If you want it thick and tough put more paint on. But once painted is easy to touch up anyway. Whether you strip of toe rail or deck is up to you. I did not. olewill

 

[yoda]

I would use Gelcoat. All the boats I have seen done by Spencer have been first class. He developed the technique with Princess Yachts I believe and I know they continue to use the same practices from time to time.

Yoda

 

[Avocet]

I replaced Avocet's topside gelcoat as a DIY job because it had crazed all over. I assume ultraviolet damage because it was worse on the areas that got the most sun (i.e. almost non-existent under the stern counter). I did it as a DIY proposition with a great deal of advice and guidance from Oldsaltoz of this parish, using the method William H describes. Without doubt, I have a better-adhering and more durable surface than if I'd used polyester, BUT if there is one drawback, it's that the mixture of epoxy and microballoons is brown and the paint is white. If anything damages the paint or scratches through it, you can spot it a mile off. I too didn't go with Awlgrip/craft but mainly on grounds of cost. Touch-up is relatively easy, but with a gelcoat, you can tolerate deeper chips / scratches and not really see them until you're quite close.

I'd also add that if the hull (as Avocet's does) has a moulded caveta (cavita?) line / cove line / rubbing strake, it makes the job at least 10 times harder! It's an insane amount of hard work and it took me a very long time. Whatever your re-gelcoating professional charges, it won't be enough!

 

[jwilson]

I have seen several successful topside re-gelcoating jobs, and one that failed quite significantly. All done by the same professional, who blamed the failure on the hull being too damp. It is a LOT more physical work than paint, as you have to longboard it smooth and then polish after application.

Personally I would always paint in preference to re-gelcoating. The higher the value (either in ££££££ terms or in sentimental value) the better an option sprayed Awlgrip two-pack is - you won't see many billionaires superyachts that are not Awlgripped. For lower value boats one-pack enamels are pretty good, if you are a decent painter, and easier and cheaper to redo every 5-8 years.

 

[ghostlymoron]

This is the perennial question and has been covered endlessly on this forum.
The conclusion I've come to is:-
1. Cut back and polish if you can
2. Re gelling is best but expensive (although I was not aware of the shortcomings of polyester that OleWill mentioned)
3. Two pack epoxy paint is more durable than single pack but is more tricky to apply and more expensive.
4. Single pack is easy to apply, cheap and reasonably shiny.

I've only painted a boat once, it hadn't been painted before but the gelcoat had damage so cutting and polishing wouldn't work. I found that getting a perfect finish by rolling and tipping wasn't easy and my finish looked ok from 10' away but didn't bear closer inspection. As for durability, I can't comment as I sold the boat soon after

 

[lw395]

I am really confused about this idea of redoing gel coat. Will professionals do it? Is it only because owners want to replace original finish? AFAIK it would be bad thing to do. Gel coat is polyester resin with a pigment for colour. It is painted on to the mould as a first layer. It can be thick or multi layered. It is then covered with the glass and resin of the substrate but the next layer is applied before the gel coat has gone hard. This means that you get a chemical bond of gel coat to the substrate. That bond is very good.
Now if gel coat is applied to an old hull it would have to rely on mechanical bonding ie the gel coat runs into uneveness of the hull to grip. .........

That is not correct. (well 'confused' might be correct....)
New Polyester gelcoat will stick to cured polyester absolutely fine.
All talk of 'mechanical bonds' is incorrect.
I can't be bothered to go into the chemistry and plastics technology again, we've had this conversation before I think.

Anyway, there are plenty of people with the skills and knowledge to stick new gelcoat to old such that you can't pull it off.

Having said that, a good two pack sprayjob is likely to look better, be harder/tougher and cost less.

If you've got a small boat that will go in an automotive spray shop, that can be very cost effective.

As with any work on older boats, there are many reasons why it may not turn out 100% as good as it should. Whatever you're putting on, porous, contaminated gelcoat is probably no1 enemy.

 

[Javelin]

In my experience the costs are similar.
However they are both reliant on man hours more than material costs.
Fairing the hull before with paint systems or after with gelcoat is what takes the time.
Gel coat is almost half the cost of quality spray paint like Awlcraft 2000.
A quality paint finish is down to the prep which is where all the hours go.
With gelcoat the man hours are all at the end of the process.
The issue with gelcoat is applying lots of thin coats to avoid tiny air bubbles which will appear when cutting back later.
Getting the gel to stick is easy as long as you get a good key to begin with.
The issue with paint is usually dust control and the skill of the guy doing the spraying.

Most yards are geared towards paint rather than gelcoat as in general this is asked for more often.
I've sprayed gelcoat but I find I have more success using a roller as its a lot less wasteful and saves a lot of time not having to tape and sheet everything every time.
With paint spraying we probably tape and sheet four or five times which on a 40' boat would take at least half a day each time.