76SeaRay
Lieutenant Junior Grade
- Joined
- Aug 24, 2017
- Messages
- 1,071
I believe all the gelcoat on my boat is 1976 original. Almost everywhere it was chaulky and on the flat surfaces with direct sun it is heavily oxidized. I only planned to do the hardtop, intermediate hardtop, and the deck above the rub rail. However, I was just buffing the transom so I can install the transom plate and gimbal housing and found that in places what looks like slight discoloration appears to be thin gelcoat. Right now it appears I will need to gelcoat the transom due to the thin gelcoat. Additionally, I crawled under the boat and trailer to see what the condition is of the gelcoat there. It looks worn and with scratches and chips so it needs to be done as well when I pull the trailer to blast and repaint it. I have never applied Gelcoat so I end up with questions. I didn't see anything in the stickies and searches haven't located a good summary of these questions.
Gelcoat Coverage
I plan to spray Gelcoat with Duratec (1:1) on the hardtops, deck and transom. So, what coverage can I expect? As far as thickness goes when using Duratec, do you apply two coats where you would normally use one coat of Gelcoat without Duratec? If covering old but sanded gelcoat, do you still apply 20 to 25 mils or just a good coating?
Surface Preparation
On the hardtops and deck, have used 40 grit to get down to clean gelcoat. I did sand through in a couple of small spots and see a few thin spots. I have ground out spider cracks and plan to refill those with polyester putty and fairing compound if needed. I plan to go over the surfaces again with 100 or 120 grit, wipe down with acetone and then spray gelcoat with Duratec. Am I missing anything here?
On the transom, I have done some sanding to prep it using 220 grit and I still see some shine. Do I need to break all the shine with more aggressive grit or is 220 grit ok?
On the hull bottom, I plan to use 40 grit then apply the gelcoat without any other sanding. Any issue with this approach to the hull bottom? Do I need to go over the bottom with a finer grit sandpaper or is the 40 grit good enough?
Gelcoat Application
What is a good batch size for the gelcoat? I read somewhere that 5 ounces is kind of the maximum batch size due to the limited time. Is this correct or can a large batch size be made up.
I have a gravity feed spray gun for gelcoat with a 2.4 tip. I plan to spray the hardtops and the deck. I assume no issues with this.
I am planning to spray the transom but it is a large vertical surface. Is it better to roll the transom to avoid runs? Does Duratec make it more likely to run since the gelcoat will be thin?
On the bottom of the hull, I am thinking I will roll on the gelcoat since it is hard to spray up from the bottom and it isn't really a visible surface. Does this sound like a good approach? Is there any specialty additive for the hull bottom gelcoat?
Finishing the Gelcoat
It will be several months before I get all of this gel work done. Is there any problem with letting it cure for that long before doing finish sanding, cutting, and buffing (I wouldn't think so)? I will probably have further questions at that time.
Thanks, maybe the answers can be added to the stickies...
Gelcoat Coverage
I plan to spray Gelcoat with Duratec (1:1) on the hardtops, deck and transom. So, what coverage can I expect? As far as thickness goes when using Duratec, do you apply two coats where you would normally use one coat of Gelcoat without Duratec? If covering old but sanded gelcoat, do you still apply 20 to 25 mils or just a good coating?
Surface Preparation
On the hardtops and deck, have used 40 grit to get down to clean gelcoat. I did sand through in a couple of small spots and see a few thin spots. I have ground out spider cracks and plan to refill those with polyester putty and fairing compound if needed. I plan to go over the surfaces again with 100 or 120 grit, wipe down with acetone and then spray gelcoat with Duratec. Am I missing anything here?
On the transom, I have done some sanding to prep it using 220 grit and I still see some shine. Do I need to break all the shine with more aggressive grit or is 220 grit ok?
On the hull bottom, I plan to use 40 grit then apply the gelcoat without any other sanding. Any issue with this approach to the hull bottom? Do I need to go over the bottom with a finer grit sandpaper or is the 40 grit good enough?
Gelcoat Application
What is a good batch size for the gelcoat? I read somewhere that 5 ounces is kind of the maximum batch size due to the limited time. Is this correct or can a large batch size be made up.
I have a gravity feed spray gun for gelcoat with a 2.4 tip. I plan to spray the hardtops and the deck. I assume no issues with this.
I am planning to spray the transom but it is a large vertical surface. Is it better to roll the transom to avoid runs? Does Duratec make it more likely to run since the gelcoat will be thin?
On the bottom of the hull, I am thinking I will roll on the gelcoat since it is hard to spray up from the bottom and it isn't really a visible surface. Does this sound like a good approach? Is there any specialty additive for the hull bottom gelcoat?
Finishing the Gelcoat
It will be several months before I get all of this gel work done. Is there any problem with letting it cure for that long before doing finish sanding, cutting, and buffing (I wouldn't think so)? I will probably have further questions at that time.
Thanks, maybe the answers can be added to the stickies...
