How much working time with Seacast?

[reelfishin]

I am contemplating using Seacast on a project boat of mine here and was wondering how much working time do you have once the catalyst is added?

How much does the mix weight?
(How much reinforcement do you need to support the inner and outer walls till the stuff drys?)

My inner and outer transom walls are super thin, the inner is only like a sheet of paper and the outer is no more than an 1/8" at best. with the wood out, the rear glass is very flexible, I am concerned with it bowing out the layers or changing the shape of the curved transom?

 

[Coors]

Re: How much working time with Seacast?

Gary is the pro; he will come in
I think he braced his with 2x4's and clamps.

 

[Gary H NC]

Re: How much working time with Seacast?

With a curved transom you are going to need brace it up with the curve you need.
The Seacast is not real heavy but it gets very hot and would probably distort the fiberglass even more.It gets almost too hot to touch for about an hour or so.
Can you make a jig out of wood and clamp it to the outside?
I noticed on the Seacast site that some people actually screw plywood to the outside of the transom then fix the screw holes when its finished.

Thanks Coors, I'm not a pro by any means but did learn a lot working with that stuff...

 

[Coors]

Re: How much working time with Seacast?

Gary, you are the man.
you learned it, and posted your experience with it.
You taught us all'
Sure sorry to see you sell a good OMC'
I go hide now...

 

[Gary H NC]

Re: How much working time with Seacast?

Gary, you are the man.
you learned it, and posted your experience with it.
You taught us all'
Sure sorry to see you sell a good OMC'
I go hide now...

Thanks....

I do kind of miss the old boat but its nice to know no more gimbals and u-joints and manifolds and,and,and.....

 

[reelfishin]

Re: How much working time with Seacast?

I've been trying to picture what the support would have to look like? The boat is sitting on a trailer now and the interior of the boat consists only of a flat floor and outer hull sides. The floor is heavily gel coated over two layers of glass mat, the dash is 9 feet forward and the sides are single wall glass.
I have considered both SeaCast and wood, SeaCast will be the answer if I can find a solid, fool proof way to support the transom. To give an idea of the amount of curve at the base of the transom, if I hold a straight edge across the center with equal distances on each sides, there's about 7" on each side to the lower corners of the hull. My biggest concern is how thin the hull is, with the wood out, it's about as sturdy as a pizza box. If I support the hull cross ways at the rear, it will preserve the curve, but the heat of the SeaCast curing may expand or warp it. I know from working with fiberglass auto body parts that glass can warp with heat when adding or making a repair if your not careful. I've used that to my advantage as well in the past.
The inside skin is so thin it's pretty much of no use unless I can support nearly every inch of it somehow.

How long from the point of adding the catalyst do I have to mix the stuff and get it in place? Will I have enough time with one batch to do the upper wing areas or do you do that with a second batch after the bottom as set up some? The wing areas on this will be a challenge, the only access will be from the inner sides, the top deck is glassed down or at least set on pure resin, there don't seem to be any screws or rivets, and I don't care to have to remove it anyhow.

Is Seacast a polyester resin or an epoxy? Is there any other brands or anything that is comparable to it?

 

[Gary H NC]

Re: How much working time with Seacast?

Seacast is a polyester based compound. It was workable for at least 45 minutes to an hour after the final mixing.You don't have to pour it all at one time,they advise letting each batch cool before adding more.
Sounds like that transom will be a challenge if you go with wood or Seacast.

 

[reelfishin]

Re: How much working time with Seacast?

It wouldn't be that bad if it were either straight or if the outer skin was thicker.
I can see why they used so many pieces of wood to make up the transom.
It's a glued mesh of strips all done in interlocking layers.

I can take a tracing of the transom shape at the bottom, cut several lateral "ribs" and build an inner and outer support brace for this thing. The inner will have to have some sort of backing or liner or else the inner skin will just bulge out around the braces. The real trick will be keeping the braces or jig in place, both outside and inside and still being able to get up close to work on it and make the pour.


Does Seacast expand or shrink any while or after it cures?
How do you calculate how much you need?
My transom measures about 75" by 20" plus the two side wing areas that are about 8x10" or so.
Is it lighter than fiberglass? (I am picturing a 1.5" thick solid piece of fiberglass, and that would be quite heavy).

If I could have thought of a way to do this in wood without the hundred little pieces they used, I would have. But I think the pour in transom idea will fill all the gaps and transfer the load better to the rest of the hull.

The real trick will be trying to really clean the inner and outer skin of all wood, the inner is so thin I am afraid that I'll tear it trying to remove the wood. When it's all done, I'll add a few layers of glass to it to beef it up a bit.

I am thinking of making a temporary inner liner or support out of sheetmetal, it will be the easies to cut and from what I read Seacast won't stick to it?

 

[gcboat]

Re: How much working time with Seacast?

Here's all your answers :http://transomrepair.com/zk/

 

[tashasdaddy]

Re: How much working time with Seacast?

here's my idea for reinforcing the inside and outside. being an old carpenter, on custom houses, we had to do some really wierd forms for concrete. if it will hold concrete it will hold seacast.
use some 3/4 ply cut the radius with about and 8" back band. cut vertical supports, the width or wider that he radius board. now notch them together. to make a honey comb form. home depot and lowes sells, 'door skin' it's 1/8 " luan ply, that you reface doors with , when the kid puts his fist thru it. use several layers of door skin.

 

[Gary H NC]

Re: How much working time with Seacast?

I like TD's idea.

As far as i could tell the seacast did not expand or contract.
I used 2 and 3/4 of the 5 gallon buckets on my transom. It was over 80 inches wide and about 27 inches deep plus the risers.
I would think 2 of the 5 gal buckets would do it. Just figure 1 bucket fills 1000 square inches..

 

[reelfishin]

Re: How much working time with Seacast?

here's my idea for reinforcing the inside and outside. being an old carpenter, on custom houses, we had to do some really wierd forms for concrete. if it will hold concrete it will hold seacast.
use some 3/4 ply cut the radius with about and 8" back band. cut vertical supports, the width or wider that he radius board. now notch them together. to make a honey comb form. home depot and lowes sells, 'door skin' it's 1/8 " luan ply, that you reface doors with , when the kid puts his fist thru it. use several layers of door skin.

Thats pretty much what I was thinking I guess, I just have to figure how to attach it to the boat or simply hold it in place on the outside. The inside can be braced and screwed to the floor I guess, but I hate to put holes in a perfect floor.

I guess as far as quanity, I'll need two buckets, I figure that mine is just under 1700 square inches, maybe a bit more due to the curve.

I am considering glassing in some supports both inside the cavity and to the inner wall before I do this, I have some fiberglass panels that I cut from another boat that can be used to help this hold it's shape better?