Ready to do transom, the correct way?

[legoman67]

Well, i am thinking that sunday will be the big day for me to install the transom in our boat. I am planning on buying the materials tomorrow, but still am having a hard time grasping afew aspects. Here is my plan

1. first 3/4 ply cut, appy 1 lay of mat
2. Apply to the hull, resin and mat side in (between the hull and the wood)
3. with 2x4 on the outside, screw through the 2x4 and t holes to support the wood.
4. second 3/4 inch peice, apply 1 layer of mat to it well laying flat
5. Place on transom same as first piece, with wet resin and mat between the 2 layers of wood, adding longer screws through the 2x4's to hold it in place
6. add (how many?) layers of fibreglass(1708 again?) to the outside surface of the second surface, overlaping approx 6 inches on the sides.

Here is my shopping list:
6 gallons poly resin
2 sheets 3/4 ply
64sq ft of mat
64 sq feet of 1708(2 layers on final board?)
1 gallon acetone(to prep surface)
2 2x4's
some wax paper(between the 2x4's and gellcoat)

Please help me, i only want to do this once

 

[danond]

Re: Ready to do transom, the correct way?

Sounds like a fine plan to me. 1708 between layers might be overkill but who's counting?

 

[92excel]

Re: Ready to do transom, the correct way?

IF you are using poly then you dont want to use 1708 between ply layers as the cloth side wont adhere to the wood.. you only want to use matt to laminate ply together.

 

[legoman67]

Re: Ready to do transom, the correct way?

so 1 layer of mat between the 2 boards, and one between the boards and hull, so replace 1708 in steps 1 and 4 with mat?

 

[92excel]

Re: Ready to do transom, the correct way?

1. first 3/4 ply cut, appy 1 lay of cloth(not sure what type? thinking 1708 biax?) do i overlap the cloth? or cut just to size?
2. Apply to the hull, resin and cloth side in (between the hull and the wood)
3. with 2x4 on the outside, screw through the 2x4 and t holes to support the wood.
4. second 3/4 inch peice, apply 1 layer of cloth(1708 again?) to it well laying flat
5. Place on transom same as first piece, with wet resin and cloth between the 2 layers of wood, adding longer screws through the 2x4's to hold it in place
6. add (how many?) layers of fibreglass(1708 again?) to the outside surface of the second surface, overlaping approx 6 inches on the sides.

step 1 is acentone the entire area a few times to make sure its very clean..

You can apply one layer of ply to the hull and then apply the other layer..
The way i did it was:
cut both ply to shape.. apply your resin to both side that will be laminated together.. let it soak it for about an hour.. then apply matt cut to size to one side.. wet it out and then put the two pieces together and clamp or put weight on top to keep them tight together.. let that sit for a day. then apply to the hull

applying to the hull...
you want to apply matt to the hull.. lather it with peanut butter.. apply matt to the back side of the transom.. here you can use 1708 if you want but make sure cloth is not directly on wood or old glass.. matt has to be the first layer to old glass or wood.. and cloth can never be next to cloth...(only when using poly)
Then place the transom to the fiberglass skin and compress.. here you can us your 2x4s to act ast clamps..

let that set for a day or two

tabbing..
tabbing you want to start with csm then go to 1708 biax to tab.. increase your tabs by 2 or so inchs.. after two tab layers of 1708 then you want atleast two full wraps of the transom with the 1708 .. and every wrap extend it farther on the hull sides..

on your ply i am assuming you are using exterior grade and not pt.. as you have to dry pt for a month before it is usable..

check out my thread i just did mine.. or oops extention thread he has a great step by step

 

[legoman67]

Re: Ready to do transom, the correct way?

ok, that makes sence, the tabbing though, whats different about that then full wraps? is it just like a strip along the edges?

lets see..
1 layer of mat between 2 wood sheets
2 laters of mat between hull and wood
1 layer of CSM on outside
2 layers of 1708 on CSM


is that about right?

Sorry, but i am brand new to all this.

 

[92excel]

Re: Ready to do transom, the correct way?

tabbing is strip cut anywhere from 4 to 10 inches depending on your needs. they are to give extra strength to seems..and once cured holds everything in place for the full wraps..

TAB EXAMPLE:

Photo borrow from hull extention thread as its closer to your transom then mine.

a full wrap speaking horizontally, will overlap the tap.. cover the entire transom ..and then overlap the tab on the other side..

 

[92excel]

Re: Ready to do transom, the correct way?

1 layer of mat between 2 wood sheets
2 laters of mat between hull and wood
1 layer of CSM on outside
2 layers of 1708 on CSM

and 1708 tabbing then 2 full wraps that will cover and encase the entire transom.

 

[legoman67]

Re: Ready to do transom, the correct way?

ok, and the first layer of CSM, that needs to go right out as far as the tabbing will go(5 inches on the side)? or will the 1708 bond to the hull?

1 soak both board in resin
2 wait 1 hour
3 apply 1 layer of mat, cut to size, to 1 board
4 sandwitch both boards together
5 harden overnight
6 apply 1 layer of mat to back of transom
7 sandwitch transom to hull
8 apply one layer of CSM overlapping 2 inches
9 apply tabbing (1708) 6 inch strips, 3 on transom, 3 on hull
10 apply tabbing 10 inch strip, 5 on transom, 5 on hull
11. apply 2 full covers of 1708