Deck hatch re-core 265

[SkunkBoat]

Been juggling projects desperately trying to complete before scheduled launch...

Got this one done. Tank hatch was a little wet and glass came loose from edge. debated doing a partial repair but when I got into it I didn't stop.
I had a nearly full big can of West epoxy and some glass lying around. Turned out I needed another $100 can....and hardener... I should have used polyester resin but those West pumps are so easy...

Taking guesses on before and after weight of the hatch. Closest wins 10,000 Non-redeemable points

I tapered the outside edges of wood blocks 45 deg and dipped the glass down
then filled with thickened epoxy

Wood is 1/2" AC exterior pine. Not what I wanted but it was a reaaly good board...clear on both sides. Had a couple voids but not bad.
Can't find any "Marine grade" AB exterior douglas fir.

chopped strand mat then "buttered" wood squeezed down then gaps filled then chopped strand mat then some tabs of chopped strand mat then some tabs of 1708 and some old leftover light glass cloth

 

[Hookup1]

That looks great! And you should have no regrets for using the West epoxy. Polyester is not a good choice for doing repair work.

The deck screws are the most likely place to fail. I over drilled them, filed with epoxy and re-drilled them. Reinstalled using 3M 4000.

 

[SkunkBoat]

I just put it down. Used 4000UV also. Hopefully its not too hard to remove.

When I took off the beckson round ports, the GE silicone was stuck firm to the gelcoat but not adhered to the plastic rings at all. Definitely dripping on tank.
Thats what made me try the 4000 this time. I'm going to take up the motorwell becksons and re-seal them.
I realized the rings can be sealed down with something substantial because normally you are only removing them when they are shot.

Funny though, there is "Use Silicone only" imprinted right on the inside of the rings!

Silicone had worked great on the edge of the hatch where its gelcoat

 

[SkunkBoat]

Any guesses on the weight before and after?

 

[DennisG01]

Nice job!

I already have 256,000 non-redeemable points... I'll let someone else guess and win them

 

[Hookup1]

I wouldn't expect any significant weight change. I like the 3M 4000UV and plan to use it more often. Seems to be a better adhesive than silicone and it resists mildew. Deck ports are problematic but 4000 will help. I'm tempted to clear silicone the caps on for as often as they need to opened.

 

[Byram]

pre 75 lbs post 50 lbs

 

[Vlabruzzo]

That looks great! And you should have no regrets for using the West epoxy. Polyester is not a good choice for doing repair work.

The deck screws are the most likely place to fail. I over drilled them, filed with epoxy and re-drilled them. Reinstalled using 3M 4000.

Why do you feel poly isn't a good choice? Grady were built with poly. Also, gel coat isn't best on top of epoxy from what I understand.

 

[Hookup1]

Why do you feel poly isn't a good choice? Grady were built with poly. Also, gel coat isn't best on top of epoxy from what I understand.

Polyester is inexpensive and works well for new layups of boats. It's hard to bond to (poor adhesive properties). Its fine for cosmetic repairs (think Bondo) but if you are doing structural repairs epoxy is a far better choice.

WEST SYSTEM Epoxy vs. Polyester

Epoxy vs. polyester: Which is the better choice for fiberglass boat repair? Tom Pawlak explores the advantages and disadvantages of each.

www.epoxyworks.com

 

[SkunkBoat]

In the case of this hatch cover, polyester would have been good choice. I had a clean, sanded original piece...the "skin"...and I was building everything else new. I don't need to gelcoat the finished product.

Polyester is HALF the price. I would have saved $100. ...except I probably would have miscalculated my pot time and wasted a lot ( heheh alot more than the epoxy I wasted).

and I hate the smell of poly.

I already had some West epoxy and slow and fast hardener and the pumps and filler.

 

[Vlabruzzo]

Polyester is inexpensive and works well for new layups of boats. It's hard to bond to (poor adhesive properties). Its fine for cosmetic repairs (think Bondo) but if you are doing structural repairs epoxy is a far better choice.

WEST SYSTEM Epoxy vs. Polyester

Epoxy vs. polyester: Which is the better choice for fiberglass boat repair? Tom Pawlak explores the advantages and disadvantages of each.

www.epoxyworks.com

Won't argue those points, still not advisable to use gelcoat over epoxy.

 

[Hookup1]

Won't argue those points, still not advisable to use gelcoat over epoxy.

I agree. When I repaired my anchor locker hatch I sprayed it with a 2-part polyurethane primer before spraying gel coat.

 

[DennisG01]

Won't argue those points, still not advisable to use gelcoat over epoxy.

Actually, while that has typically been the thought in the past, it's been proven that gelcoat bonds perfectly well with epoxy. Possibly it was based on older formulations of one or the other.

And, yes, poly would have been completely suitable for the job. But, like Skunk said, it's a bit harder to work with (pot life) and is quite stinky.

 

[Hookup1]

Actually, while that has typically been the thought in the past, it's been proven that gelcoat bonds perfectly well with epoxy. Possibly it was based on older formulations of one or the other.

It's my understanding that it may interfere with the curing of the polyester gel coat resulting in a sticky finish. Do you really want to take that chance on your project? Could have to do with formulation changes over time.

I'm not taking any chances. In fact I may move off using gel coat altogether and go to a marine 2-part polyurethane for finish coat.

 

[DennisG01]

It's my understanding that it may interfere with the curing of the polyester gel coat resulting in a sticky finish. Do you really want to take that chance on your project? Could have to do with formulation changes over time.

I'm not taking any chances. In fact I may move off using gel coat altogether and go to a marine 2-part polyurethane for finish coat.

With what I've read and seen over the last 5 years ago, yes, I would have no issues in doing it. At this point, it's kinda like the old suggestion to never store a battery on concrete because it will cause it discharge... which also is no longer true (but used to be a long time).

 

[SkunkBoat]

pre 75 lbs post 50 lbs

so the answer was 87 vs 66...21 pounds lost.

 

[Hookup1]

Epoxy was the right answer. No looking back. Nice job!

Weight? Looks like less angels on the pin head.

 

[SkunkBoat]

Epoxy was the right answer. No looking back. Nice job!

Weight? Looks like less angels on the pin head.

overall yes...but when its YOU trying to pick it up and get it out of the boat that 21 pounds was crushing....

 

[pmgia]

I had mine redone with Coosa. It’s lighter and stronger than before. No chance of water getting in there again. Someone had put a small hole under the leaning post for a wire that leaked water into the core and saturated the tank cover. Better than new now. I did the small cover too, didn’t need it but since we were in there I didn’t want issues later.

 

[Keith_274]

Thanks, that helps