fiberglass layup schedule

[Ed]

Will-

While roven woven may work in this instance, I would use the following layup schedule because it offers (in my opinion) better adhesion.

2 layers of 1.5 oz mat
1 layer of 1.5inch Coosa
1 layer of 1.5 oz mat
1 layer of 1808 biaxial
1 layer of 1.5 oz mat
1 layer of 1808 biaxial
1 layer of 1.5 oz mat ( this layer is optional....it seals off the last layer of 1808 and prevents any strands from fraying, etc.)

The important thing is to make sure that each layer of laminate is progressively longer and taller and overlaps the previous piece. This will assure that each laminate is bonded to the hull versus having all layers bonded to the first laminate.

Hope this makes sense.

Ed

[pogden]

Ed,
I have 3/4 oz mat, would that be sufficent in the lay up?
I had heard that it is good to use mat in between WR, but was also told that epoxy doesn't penetrate mat very well.
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[WillyC]

Ed and Pat,
Many thanks. Thats exactly what I'm looking for.

Pat,
I contacted the manufactor of Coosa and spoke with a company rep. They gave me the name and number of the closest distributor which for me was in New Orleans. The following link is their web address. I went with the blue water 26 because it is their strongest grade (density of 26 lbs per square foot). No rot and 30% lighter than plywood. It is expensive but not that much more than two sheets of 3/4 inch marine ply. They emailed me some spec sheets of some of their products. I will forward them to you if you are interested. Thanks again -Will

http://www.coosacomposites.com/

[rockdoc]

Ed, (and others)

What are the pros and cons of doing an "inside job" versus an "outside job" on a transom replacement? In other words, cutting the outer skin (ouch) or the inner skin of the boat? I imagine an inside replacement is preferable, and easier if the floors and stringers are getting work also.....And, in your layup schedule recommendation, which are the inner and outer laminations? I'm assuming the 2 layers of 1.5 oz mat are inside, just thought I'd ask to make sure.

Thanks!

Steve

[rockdoc]

Ed,

One more question:

are your layup recommendations to Will for the thickness of an entire transom, or just in addition to the glass that's still there (the outer shell in his case).

Thanks again!

Steve

[warthog5]

West System's 5 to1 epoxy is what I would NOT use in doing this job. Your going to need a epoxy that has a longer pot life.
Even with a longer pot life you will be rushing.
A 2 to1 like Raka or System 3 or FGCI's 2 to1.

[WillyC]

Jim,
How did you remedy your thickness problem on the 20 footer?
As I recall when removing the splashwell and boxes/seats there was room inbetween the transom and backs of the seats but the top of the splash well was butted against the transom. This is making me a little nervous. Maybe I should have ordered the 1 3/8 inch coosa board.

Ed,
Do you think it would be ok to layup the two layers of mat and then secure the core with the glue and screw (thru bolt) method. Let that cure and then finish the rest of your layup schedule all in one shot. Thanks -Will

[warthog5]

QUOTE: Do you think it would be ok to layup the two layers of mat and then secure the core with the glue and screw (thru bolt) method. Let that cure and then finish the rest of your layup schedule all in one shot. Thanks -Will


That's what I would do to make sure that the core is beded well and no voids.

[WillyC]

warthog5,
Thanks for the info. Do you think I should layup the mat on existing transom skin and let that cure before bonding the core or just lay both the core and the mat at the same time.
P.S I've been following your progress over on the mako site and check for updates almost daily. Very nice work!

[EBEACH]

Will,

I used a grinder to remove some of the wood in that area. Do a dry fit before glassing in everything. You can also grind the splash well a bit thinner. You'll want to make up a putty mix and trowel it on the core and then clamp it into place. It's two steps, glue the core in place and then come back later and laminate the the core.

I used chopped mat on both the skin and the core, but you will need the putty also. I'm using Ployester and currently waiting for cooler temps.