inside or outside

[tangofniro]

I plan on using some 1/4 luan. Should finish up the foam removal today. I plan on using epoxy just not west.
'You laid 2 layers of glass before you even started installing the new core? How long did you wait before installing the core on the old skin?
Anymore have good ideas on templates to use on the transom besides cardboard?

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YOU CAN START ANY TIME YOU LIKE FROM TACKY TO HARD BUT RUFF SAND IF IT HARDENS. I USED A SHEET OF 1/8 “ WOOD WALL BOARD ATTACHED IT TO THE OUTSIDE OF THE HULL WITH CLAMPS TOOK A PENCIL AND TRACED THE BOTTOM OF THE HULL DESIGN ON THE WOOD CUT IT OUT (INSIDE THE LINES) AND IT FIT PRETTY GOOD I THEN GROUND IT TO EXACTLY FIT. AFTER THAT YOU CAN TRACE THE NOTCH IF YOU ARE NOT GOING TO INSTALL A BRACKET BUT WAIT UNTIL YOU GET YOUR BOTTOM FITTING CORRECTLY FIRST BEFORE YOU CUT IT OUT.
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[Rich]

I did mine from the outside. Cut the outer skin 2" from the edge all the way around. I cleaned out all the wet wood and ground down to the inner glass. I used a method of multiple layers of 1/4" luan soaked with epoxy, and 1708 biaxial cloth that I got from Raka.com. I tried to get fancy with cardboard and make a template, but that didn't work too well. I took a full sheet of Luan and strapped to the back of the transom and traced around the outside to get the template, than adjusted accordingly. I first rolled out and saturated each cut sheet of luan with slow cure epoxy. I did each piece twice. The lay up was as follows:

Laid first sheet of luan flat, pre cut cloth on top of that, wet out thoroughly with slow cure epoxy. Placed that combo with the wet surface up against the inner liner and temporarily screwed it into place. Followed that procedure 5 more times within an hour's time. I built it up just enough to allow the outer skin to go back on and fit flush. Using different methods with screws and clamps, I pulled everything together and let it cure. To fill the voids around the outer edges I took cut strips of 1708 cloth soaked in Epoxy and jammed it into the empty spaces. I took the old outer skin cleaned it up, covered it with a thickened epoxy (cake mix consistency) and smeared it all over the inside of the outer skin. Set that in place and clamped it down.

Faired with thickened epoxy to get everything flush and looking good.

I raised my Transom from 25" to 30" in the process.

Advice:

Make sure you have a couple of people around to help. Because of obvious time constraints, things can get messy. I had the help of two other people.

Make sure you have PLENTY of epoxy. I almost ran out. The cloth that I used, the 1708 Biaxial from Raka is thick and really sucks up the epoxy. I think I went through 2 1/2 - 3 gallons.

Don't get over zealous with mixing up huge quantities of epoxy. Once it starts to kick in a large mass, it's all over. We would mix up enough to thoroughly wet out the cloth on top of the next sheet of luan and then repeat the process.

Needless to say, I don’t have to worry about the transom anymore.

Going from the outside worked for me. I didn’t have to cut up the inner liner for any internal structural problems or modifications. Going from the inside would have been a lot more work for my situation.

http://www.classicseacraft.com/cgi-b...c;f=3;t=000034

My 2 cents……

[ April 02, 2003, 02:50 PM: Message edited by: Rich ]

[abl1111]

What is Luan ? I will be re-doing the transom in my Tsunami as soon as I can pull/sell the (2) i/o's I have in there now. I'll also be removing present engine stringers and installing new ones for a single i/o. Has anyone done this job that you know of ?

I will be going from the inside and was planning on using (2) 3/4" pcs of plywood and polystyrene resin as replacement.

As for tools to get the old core out ? I can get my hands on a compressor - if I was to buy a tool for the compressor to remove the core, what would it be ?

[tangofniro]

Luan in the simple explanation is just finished plywood, no knots.

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HA ABL1111
I ALSO USED 2 ¾” SHEETS OF PLYWOOD ON MY 23’ BUT IF I WAS GOING TO USE PLYWOOD AGAIN I WOULD USE 3 SHEETS OF ½” INSTEAD. IT IS A LOT EASIER TO WORK WITH AND WHEN YOU WERE DONE YOU WOULD HAVE 6 SIDES LAMINATED WITH RESIN INSTEAD OF JUST FOUR. THAT COULD HELP IN THE RESISTANCE OF WATER DAMAGE IN THE TRANSOM AS THE YEARS GO BUY. I ALSO WOULD USE EPOXY RESIN NOT POLYESTER RESIN YOU CAN PROLONG THE TIME BEFORE IT STARTS TO HARDEN WITH THE CATALYST YOU USE. THAT WILL HELP THE RESIN TO PENETRATE INTO THE PLYWOOD AND KEEP IT FREER FROM ROT. AS FOR TOOLS I USED A GRINDING WHEEL ON A HAND GRINDER IT CUTS THROUGH FIBERGLASS LIKE BUTTER. ON A COMPRESSOR I GUESS YOU WOULD USE THE SAME ¼” GRINDING WHEEL MAYBE A 1/8” THICK. YOU ALSO MENTIONED SOMETHING ABOUT REMOVING YOUR I/O STRINGERS FOR A OUTBOARD STRINGER SYSTEM I DON’T KNOW ANYTHING ABOUT ANY POTENTIAL PROBLEM REGARDING THAT PERHAPS SOMEONE ELSE COULD COMMENT ON THIS IF THERE IS A PROBLEM (I THOUGHT THE STRINGERS WERE THE SAME).
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