transom question??

whisker

Petty Officer 3rd Class
Joined
May 17, 2006
Messages
91
hi ,
guys im still debating on getting my local marina to install coosa board transom and stringers .all this will set me back 3000.00.. my wife thinks the money can be used else where. so im thinking about doing it myself to be cost effective..
if i choose to do it myself.. i was thinking of using fir..if i use fir do i coat the board in epoxy or poly.. then to i need to put a filler on the back of the board that will but up to the fiberglass for the transom to avoid any holes ? how much filler do i use? just a few questions to see if i want to tackle this myself..
 

andy6374

Lieutenant Commander
Joined
Aug 4, 2005
Messages
1,617
Re: transom question??

This is long post, but you wanted to know what was involved in the transom core replacement. Here it is in a nutshell

Are you going to work from the inside or the outside. Working from the inside is easiest for the DIY'ers.

Typical schedule (variable to the you personal taste though!):
- Get the old core out. This may mean cutting the stringers back a few inches. The stringers may have some rot anyways, so cutting back to good wood might be needed.
- Grind down the old skin to some good fiberglass, ie no black delaminating fiberglass.
- If you have 90 degrees corners between the bilge/hullsides and the transom skin....run some fillets along those angles. This will help the glass conform easier as well, not to mention that curved corners are much stronger than 90 degree ones.
- If the grinding has left the transom skin thin and weak, I'd beef it up with some layers of glass.
- Don't know how big your boat is, but a typical transom core is made from 2 sheets of 3/4" marine grade ply laminated together. First soak each sheet (back,front and edges) with resin (epoxy, poly, vinylester). You can either laminate each sheet together with 1-2 pieces of mat or trowel some resin/milled fiber/cabosil putty mixture on each sheet and clamp them together. I like to use the putty because IMO it leaves no room for voids.
-Take the same putty mixture and trowel it onto the transom skin and the new core, taking care to put alot of putty around the angle between the bilge/hullsides and the transom skin.
-Drop the transom in clamp it in or use some thrubolts. This will squeeze all the excess putty out (no air voids 8)). Then make a nice fillet around the perimeter of the new core.. Your done.
-Now wet out 3-4 overlapping layers of glass over the new core to form your new inner skin.
-reattach the stringers....
 
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