seacast transom
 

im considering using seacast for my transom. any comments or opinions on this stuff? i figure it would be alot stronger considering ill be puttin a 250 on her

Re: seacast transom
 

In a word, no. I have seen seacast used on boats and first it is very heavy, 2nd it can crack over time. Simply put, glass over marine plywood will last 20-30 years.

Re: seacast transom
 

I have used it a few times with good results. :rolleyes:

Re: seacast transom
 

Herm, No offense but have you seen the seacast after 3,4, or 5 years? Why would someone choose that over wood or a cored product? :o

Re: seacast transom
 

Briguy

What happens to seacast after 4-5 years

Thanks

Dave

Re: seacast transom
 

Anyone know what seacast is . . . I always thought is was some combination of 1/2 chopped strand, cabosil, talc, and resin?

Re: seacast transom
 

It is a mix of proprietary resins and recycled ground fiberglass. You add the supplied ground glass then catalyze with BPO cream hardener. It is in my opinion only a good idea to use when the core is totally rotten to mush and the boat transom has a good existing laminate.

Seacast is a core material so you need a sufficient laminate on both sides of the material to provide the strength.

Proper preparation is key to achieve good results. They have a pretty good website with step by step instructions for use.
transomrepair.com :D

Re: seacast transom
 

I poured my transom,in my opinion if you plan to keep the boat for any length of time it's the only way to go it bonds better because all the voids are gone.

Re: seacast transom
 

Well if it can handle twin 250's then that's probably a good indication to go ahead and uses it.

Re: seacast transom
 

Years ago i was heading down the path of using Seacast.

Yes, i was handy with a chainsaw and removed the transom core from the top!! :eek:

The main reason i decided against using Seacast was the fear of it cracking.

Decided to use the tried and true plywood method.

Ah yes, good old days ... chainsaws and boats! :D

- Nick

Re: seacast transom
 

I used arjay ceramic pour in my transom,not seacast real
easy to use hard on drillbits, price was better also.it
holds 250's well
http://teamsouthbound.com/picturepro...afts%20028.jpg

Re: seacast transom
 

There are many pourable fillers available nowadays. Here is another incorporating the ceramics,

NIDA-BOND POURABLE TRANSOM COMPOUND is ceramic filled polyester exhibiting exceptional physical properties. In particular, the compressive strength has been documented by an independent testing laboratory to be 3,895 psi (ASTM 695). This is several times that of plywood and 8 to 10 times that of PVC foam. In addition, the failure mode shows elastic yielding before failure. This makes the NIDA-BOND POURABLE TRANSOM COMPOUND material an excellent choice for critical applications such as coring transoms on power boat hulls. web page

http://www.nida-core.com

Re: seacast transom
 

Hermco or anyone familiar, could you give me a ballpark guess how much poorable product it would take for a transome similar to this?
http://img.photobucket.com/albums/v6...kender/19a.jpg

Re: seacast transom
 

web page :D

Re: seacast transom
 

thanks Hermco, boat is 150 miles away right now, I was hoping you had a guess, 5 gal, 10, 15?

Re: seacast transom
 

Hey I know that ass end! :cool: just for the record its a marine plywood core ;)

Re: seacast transom
 

Do the math. :D

Re: seacast transom
 

Rough numbers, 2" thick, 25" transom 8' beam will be about 20.5 gallons... I suck at math so your numbers will vary. Take Hermco's advice and do the math...

Re: seacast transom
 

I looked into plywood and Nida-core materials and decided on Nida-Core pourable. I had a gallon sent and did some lamination testing and strength testing and found it to be fine for what I'm using is for in my transom with a 250 and 30" shaft. The function the core is to separate the outer skins and keep them bonded. Your strength is in the inner/outer fiberglass skins, not the core. Think of a balsa cored boat - how much strength is balsa adding???

D-

Re: seacast transom
 

I just got through doing my transom w/ seacast,
its interesting stuff.

Use unwaxed poly resin,
promote it with DMA .05% by volume.
Add some cabosil to prevent the resin from draining out of the mix. A texture like thick corn syrup is a good starting point.
Store this a couple of days, catalyse with bpo (benzoyl peroxide is available at ace hardware for using with bondo putty) add chopped fibre and its ready to pour.
Just follow the seacast directions.

dimethylaniline (DMA) available from chemical suppliers, hard to track down but its out there. It must be used with BPO or the resin will not harden, its in bondo but bondo isn't too usefull.

Re: seacast transom
 

jonesg, Congratulations! Interesting stuff. What's the boat, beam, transom height & thickness, and how many gallons did you use. Thanks.

Re: seacast transom
 

My boat isn't a seacraft, I have a 73 Chrysler Center console 20' . ended up joining here simply because of the level of expertise evident in the repair projects.

I needed 3 x 5 gal buckets of seacast but bought 2 instead to save $220, made up another 5 gals myself after checking the seacast out.
They package a lot of extra chopped fiber and I still have a load of it leftover so no need to buy more.

This book by John Wills has lots of resin formulas to make up your own concoctions.
He was involved in discovering how to make polyester resin catalyse at room temps 50 yrs ago.
For $16 its an interesting read even if you don't plan on making up your own mixes.
http://johnawills.com/indpu.html

Re: seacast transom
 

Interesting reading to be sure. Finally, a chemistry lesson that I can take interest in applying :D
Thanks for the link.
Are you the author or how did you learn of these books.
Love to see pictures of the process you used, Seacraft or not. Cheers, -McGill

Re: seacast transom
 

No I'm not John Wills, I found his books on "aircraft spruce and supply" when I was ordering glass cloth.

I notice from reading the contents list from seacast it almost reads as if they don't want you to know whats really in it. It doesn't list DMA but it has to be in there or the resin simply will not work. NA will not work with BPO.

Seacast is a great product though, I wouldn't hesitate to recommend it, I just like making things myself.

The only occurance of cracking is some guy tried to make a jackplate from seacast, thats a misapplication methinks.

Will's book has some funny recipes, poor mans parting film can be made by dissolving old movie reels in acetone, thats how they used to make it and why it had a blue green tint.
Todays concoctions are tinted with dye to simulate the old method.

Re: seacast transom
 

I used Seacast in my 30ft Scarab with 2-225 about 5 yrs ago it was our first try at it turmed out very good and still holding. The second 2 trys were Hydro Streams turned out very nice there is still a pile in the driveway I cant get off. It took 15 gals to do the Scarab.