1974 20' sceptre transom replacement and i/o to outboard bracket conversion - Page 5

flyingfrizzle · #41 11-05-2013, 08:28 AM

Took off the windshild and all the hard ware off the boat. Getting it striped down and trying to fix any small spots and cracks in the gel coat. Filling any old holes from previous life:

flyingfrizzle · #42 11-05-2013, 08:43 AM

Getting the bottom paint off has been a challenge on my back so I decided after seeing how some others on here done it on their post I decided to put her over on her side. There is only one coat of bottom paint to get off and then I will sand the gel back with 120 grit then fix any small cracks or blisters with a 2 part epoxy under water filler (light green stuff on the bottom of the hull). Once that is done and I get the bottom faired in I will apply a thick coat of the the interlux 2000e epoxy seal coat to it.

uncleboo · #43 11-05-2013, 02:29 PM

Spent a lot of time in that garage! Hey Friz, the guys name is Chris Phelps and his cell number is 252-337-4452. Hope he can hook you up. Later, boo.

flyingfrizzle · #44 12-03-2013, 12:42 PM

The bottom paint is gone and all the small blisters and cracks have been repaired with an epoxy filler. I sprayed 3 coats of interlux 2000e barrier primer on the bottom of the hull and got it almost ready for paint inside and out. Once it warms up out side I will spray the whole boat with prime kote primer then wet sand it and them prep for paint.

Big fish · #45 12-26-2013, 01:51 AM

Thanks for all the great posts as I will soon be replacing my transom as well. Did you use epoxy just to the outer skin or also between plywood? And what type of resin for the fillets? I'm told that if using epoxy everything has to be epoxy.

flyingfrizzle · #46 12-27-2013, 01:16 PM

Quote:

Originally Posted by Big fish

Thanks for all the great posts as I will soon be replacing my transom as well. Did you use epoxy just to the outer skin or also between plywood? And what type of resin for the fillets? I'm told that if using epoxy everything has to be epoxy.

You are right some what on the epoxy usage. You can't apply poly over or on top of epoxy and get a good bond. You can do the opposite and go epoxy over poly or ve resin. You can use them together if you are careful on how you apply them. On the transom I used poly to make the core section before it was installed into the boat. There was a 1/4" of glass and resin between the 2 3/4" wood plys and 2 layers of Matt around the core fully sealing the wood 100 percent. Forgot to mention I thinned some of the poly resin and hot coated the wood too. The wood will soak in thinned poly better than the epoxy. I try to always hot coat wood prior to adding glass cloth and resin. The core was scuffed with 80 grit to give it some tooth to bite a bond when I installed it. Scuffed the back of the boat the same then I used the epoxy to bond the sealed wood core to the old 40 year old glass on the transom skin. I only used the epoxy to bond the core in place only. Once that was in place I added several layers of 1708 and tabbing to the front of the core out of ve resin. The filets were made from ve resin thickened with cabosil and fiberglass rice pellets. The epoxy did not get any other resin bonded to it. It is just between the core and boat skin only. All the ve on the opposite side of the core never contacts the epoxy. There may of been some slight contact under the filets were some epoxy squeeze out around the core but bond is not as important there. I usually only use epoxy where I need a good bond to old glass or when I make a thickened puddy for gluing or bonding parts down. Mainly situations that don't require cloth. If I am laminating cloth I mainly use the ve resin. The epoxy will give you a better secondary bond to fully cured glass or old 40 year old potter glass.

Big fish · #47 12-28-2013, 01:29 AM

Thanks for the great information. How much epoxy was used for the bonding? And roughly how much ve resin for the rest? Will poly resin work also? Prices here are 65/gal for ve compared to 38/gal for poly. Sorry for all the questions as this will be my first time repairing a boat.

flyingfrizzle · #48 12-28-2013, 08:47 AM

Quote:

Originally Posted by Big fish

Thanks for the great information. How much epoxy was used for the bonding? And roughly how much ve resin for the rest? Will poly resin work also? Prices here are 65/gal for ve compared to 38/gal for poly. Sorry for all the questions as this will be my first time repairing a boat.

I'm don't remember but know it was less than a gallon of epoxy. It did take a lot of cabosil to get it thick enough to apply and hold in place without it running. The rest of the lay up took around 3-5 gallons to do the transom. Sorry on the vague numbers but pulling out of a 55 gal drum it is hard to keep up with it. I think a 5 gal kit would come close to do the transom and I would use a good quality vinyl enter resin. The bonding strength is much stronger and it is much more water resistant. Poly is fine and will work too but the ve is much better. Epoxy will be best but not much better than the ve. If saving money is a must use the poly to build the core, filets and use the ve to do the bonding to the old glass for a better secondary bond.

Big fish · #49 12-31-2013, 12:52 AM

Is vinyl ester much better than poly resin? I'm probably going with epoxy for core to outer skin and wondering how much better ve is to poly. Cost is somewhat an issue but piece of mind is most important. I don't want to have any doubts or regrets.

flyingfrizzle · #50 12-31-2013, 01:31 PM

Quote:

Originally Posted by Big fish

Is vinyl ester much better than poly resin? I'm probably going with epoxy for core to outer skin and wondering how much better ve is to poly. Cost is somewhat an issue but piece of mind is most important. I don't want to have any doubts or regrets.

The elements of boat strength by David Gerr has a chapter on this. (A great book to own)
Ortho - polyester will elongated about 2% before cracking the tensile strength is 9,400 psi

iso-polyester is about the same but is more resistant to chemical attack

Vinylester will elongate 5% before cracking, the tensile strength is 11,800 psi

Epoxy will elongation is usually more than 5% and a tensile strength of 12,500

Ve and epoxy is water resistant when poly is not. If you use a high strength glass like 1700 biaxel or 1708 you need the strength of the ve or epoxy. The polyester resin will fail well before the fibers will and you will loose the potential strength of the lament due to it is not strong enough to get the full potential strength out of the cloth. There are many poly made boats that are plenty strong but with the ve or epoxy you will get a much stronger, waterproof and durable product. I would use the ve on any situations that requires high strength.