Painting over epoxy coated ply

Kelpie

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My little nesting dinghy project is coming along nicely (actually it's not seeming so little, it seems enormous but I'm hoping that much like a Christmas tree it will seem smaller once I take it outside!)

The boat is built from 5mm Robbins Elite ply, and will be coated in three layers of epoxy. The chines etc are also glass taped.

I have been reading up on the pros and cons of one and two pack finishes. Since I have the boat in a perfectly dry and warm workshop I could go with two pack, but I won't have this opportunity again and I imagine that after a few years as a daily use tender it will need some TLC. It will be much easier to touch up with one pack.

So I'm thinking about going half way- use a 2 pack primer, then 1-pack over the top. The fact that I have a plentiful supply of Toplac left over from a previous project also helps this decision.

Any thoughts?
 
My little nesting dinghy project is coming along nicely (actually it's not seeming so little, it seems enormous but I'm hoping that much like a Christmas tree it will seem smaller once I take it outside!)

The boat is built from 5mm Robbins Elite ply, and will be coated in three layers of epoxy. The chines etc are also glass taped.

I have been reading up on the pros and cons of one and two pack finishes. Since I have the boat in a perfectly dry and warm workshop I could go with two pack, but I won't have this opportunity again and I imagine that after a few years as a daily use tender it will need some TLC. It will be much easier to touch up with one pack.

So I'm thinking about going half way- use a 2 pack primer, then 1-pack over the top. The fact that I have a plentiful supply of Toplac left over from a previous project also helps this decision.

Any thoughts?
Not on the question you asked, but what nesting dinghy design are you building? I've admired the dinghy used by sailing Florence on YouTube and quite like the idea.
 
My little nesting dinghy project is coming along nicely (actually it's not seeming so little, it seems enormous but I'm hoping that much like a Christmas tree it will seem smaller once I take it outside!)

The boat is built from 5mm Robbins Elite ply, and will be coated in three layers of epoxy. The chines etc are also glass taped.

I have been reading up on the pros and cons of one and two pack finishes. Since I have the boat in a perfectly dry and warm workshop I could go with two pack, but I won't have this opportunity again and I imagine that after a few years as a daily use tender it will need some TLC. It will be much easier to touch up with one pack.

So I'm thinking about going half way- use a 2 pack primer, then 1-pack over the top. The fact that I have a plentiful supply of Toplac left over from a previous project also helps this decision.

Any thoughts?

2 pack will 'bruise' less, so need less touching up. 1 pack will be easier to touch up. Awkward balance.
I have a car painted in 2 pack. However the paint shop supplied me with a small pot of touch-up which is pre-mixed, but does not go off in the pot and air-dries. don't ask me how.
 
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My little nesting dinghy project is coming along nicely (actually it's not seeming so little, it seems enormous but I'm hoping that much like a Christmas tree it will seem smaller once I take it outside!)

The boat is built from 5mm Robbins Elite ply, and will be coated in three layers of epoxy. The chines etc are also glass taped.

I have been reading up on the pros and cons of one and two pack finishes. Since I have the boat in a perfectly dry and warm workshop I could go with two pack, but I won't have this opportunity again and I imagine that after a few years as a daily use tender it will need some TLC. It will be much easier to touch up with one pack.

So I'm thinking about going half way- use a 2 pack primer, then 1-pack over the top. The fact that I have a plentiful supply of Toplac left over from a previous project also helps this decision.

Any thoughts?
there is no doubt about the dinghy getting knocks and scrapes. We paint ours with two pack using a roller. It gets touched up on our foredeck so no problem doing it anywhere. The two pack also dries quickly. We are doing a painting project at the moment and stumbled on a near perfect roller for two pack paint. Wickes foam rollers for gloss. The paint needs no tipping off if you get your technique right. I would definitely go for two pack paint.
Also consider adding some kevlar to the bottom of the dinghy on the vunerable bits. Alternatively, even E glass would be more durable than ply
 
Jotun Penguard epoxy system went on beautifully on the epoxy (resin) coated ply I rebuilt some of our bulkheads with before the latest lockdown. For a two component, it’s very easy to mix/apply and you only need a mask while applying in a very confined area - within half an hour or so it stops smelling. As it’s proper amine-based epoxy, it also provides added water resistance. Or you can go the whole hog with the amine and aluminium based Jotamastic 87. That’s their most water resistant formulation.

Best part is they all cost around £50 per 5l and have lots of other uses on the boat.
 
I would go with 2.

I am forever impressed how much better this stands up, and will last for many many years longer.

I am not sure why you are concerned about touching it up without recourse to a dry workshop. I have not had any issues working with 2 pack outside, obvioulsy choose your weather conditions, but with some warmth it will "set" much quicker than traditional varnish and will even take some rain once it is set and not fully cured.

Of course if you ar trying to preserve a show room finish you wont with the need for a series of touch ups with any varnish, but I doubt you do given the use you have in mind for your dinghy.
 
Balance of opinion seems to be with 2-pack, then.
If our plans work out this will be our daily use tender whilst we are away bluewater cruising. Maybe it won't be as hard as I imagine to find the right conditions to touch up the paint. I did a full repaint of my previous 33ft boat outdoors here in Scotland and that has left me very wary of doing anything to make painting more difficult or complicated!
 
Balance of opinion seems to be with 2-pack, then.
If our plans work out this will be our daily use tender whilst we are away bluewater cruising. Maybe it won't be as hard as I imagine to find the right conditions to touch up the paint. I did a full repaint of my previous 33ft boat outdoors here in Scotland and that has left me very wary of doing anything to make painting more difficult or complicated!
Your biggest problem if you repaint in the Caribbean is likely to be the heat setting the paint off very quickly! We try to rig up some shade
 
It is easy enough repainting with 2 pack paint here in the Caribbean - here I can get slow, medium or fast hardener, and I use slow, and it still goes off fairly quickly, even in the shade.
Jotun appears popular in Thailand, based on Liz and Jamie’s refit of Esper on YT. Cure times are given to 25 degrees. You can usually manage that in the morning/shade.
 
Thoughts on Hempel 2 pack products? I need to order some more glass cloth and the supplier I used last time also does Hempel paints. Makes sense to order everything from the same place.
(Living up here you get absolutely shafted on delivery... I'll be paying £25 postage for a fiver's worth of glass tape...)
 
...and I’m hoping that adopting a paint ‘system’ (Jotun in our case - other brands are available) that you use for almost everything will make it easier when you come to cruising. That way you can carry at least the primers you’ll need for most any job. Then any locally-sourced topcoat can do to finish it off. The only other paint we use now routinely is bilge paint.
 
...and I’m hoping that adopting a paint ‘system’ (Jotun in our case - other brands are available) that you use for almost everything will make it easier when you come to cruising. That way you can carry at least the primers you’ll need for most any job. Then any locally-sourced topcoat can do to finish it off. The only other paint we use now routinely is bilge paint.

What's the compatibility like between different brands of tw-pack? Are they all using basically the same chemistry?
 
I wouldnt bother carrying a load of paint just for the dinghy. Any automotive two pack poly will do. You can buy that all over the place. We had some Awgrip left over from painting the cockpit that we also used for the dinghy. Its nice to have paint that does several jobs. Space gets tight when you are living aboard and you will definitely being adding stuff as you spend more time living aboard.
 
As Steve1963 says, why not use 2 pack and later touch up with one pack. I’ve been doing this on my racing dinghy for the past 14 years, with a total rub down and repaint in one pack about every 5 or 6 years. It has the durability of 2 pack without the maintenance hassle.
 
As Steve1963 says, why not use 2 pack and later touch up with one pack. I’ve been doing this on my racing dinghy for the past 14 years, with a total rub down and repaint in one pack about every 5 or 6 years. It has the durability of 2 pack without the maintenance hassle.
I think the difference between maintaining a racing dinghy and a dinghy that will be your everyday ride is quite different. I would expect the OP to pick up far more dinks and knocks. I full rub down and paint may be a fairly frequent occurrence
 
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