Where is all the strenth in the transom ?

[markpeta]

Where is all the strenth in the transom where it joins to the floor or the sides or all of it. Also how does the floor tie in with the transom. Does the ply sit in the back then fiberglass get folded the inside and outside of the boat to the ply. If so how thick should it be.

Yes I found rot in the backany help would be help would be greatly recieved. Doesnt worry me to much having to do this as it gives me something to do.

The inside and out skin intact no cracking or stress.
This was going to be my approch.
1/ Take the motor off
2/ cut the back skin off
3/ Get rid of all the old timber
4/ cut new peice of marine ply coat it in resin.
5/ place it in against back skin with marine glue/resin.
6/ bond the edges around the edge to the boat in resin.
7/ glue or resin the back skin to ply.
8/ fiberglass the edges where cut with fiberglass if so how wide should i go either side.

The reason i would like to do it at the back skin is that the floor on the inside is fine as are the knees.

Please tell me if I am being stupid or any other things that might help.

Mark [smiley=bigcry.gif] [smiley=bomb.gif]

[blaze]

Hi Mark
If it was me
cut the gunnels about 600mm to remove outboard well,
remove the inner skin and at least 300mm of floor
check stringers (may not be that ok)
replace timber
reglass and tie to stringers
replace outboard well
Even the outboard well ties it all together as well as the sides and stringers
do a search been a lot of transom/rebuilds, pros and cons
you will be able to do it yourself
remember safety gear, overalls, glasses and breathing mask
cheers
blaze

[adriancorrea]

Hi Mark
Im in the middle of the same process you are going through.
I cut the inner skin off and dug out the rotten timber and as blaze said, cut the floor back about 300mm and will replace the timber and tie it all together.
Happy rebuilding Mark

Tight Lines
Adrian

[billfisher]

Make sure you use epoxy resin. It is much more adhesive than the polyester resin used to build the boat and so is ideal for repairs. Also use epoxy to glue the layers of ply together, most boat builders just staple the ply.
Do this and the repair should be stronger than the original transom.

[gofishin]

Mark

Used to do this for a living - in the tropics too where the problem is more prevalent. Previous posts are on the money & are good advice. Don't try & take shortcuts, it will cost you in the end.

Even though you think the other timber is good, it may not be. Dry rot is a fungus & sends out runners through the pores etc of adjacent timber, like invisible tree roots. As per prev, definitely leave the outer GRP skin intact, remove enough of the floor to allow you to remove all transom timber, and check adjacent timber - stringers, knees, floor etc. if in doubt, remove & replace. EPOXY is the law.

[drb]

Leave the outer skin in place if you can.

Use Unwaxed Polyester resin because.
1. It is at least half the price of EPOXY
2. Does not require sanding between layers if done with in a reasonable amount of time
3. You can use less or more MEKP to vary kick times to suit ambient temperature.
4. Your boat is almost definately made of polyester now.
5. It is much easier for an amateur to use

A few othe rtips
Add wax in Stryrene to final layer where gel coat or flow coat is not going to be used.
Make sure you sand any old surfaces before putting new glass on it.

Epoxy will soak into timber a bit better than polyester but it is often used for kit builders do glass over ply boats. If you use epoxy you must wait for every layer to go off, then sand it completely before putting on the next layer.

Dazz

[gavsgonefishing]

Actually I'm with dazb. Dont really care which skin stays. Make sure you have provision for good clamping to squeeze the air out. I would be working from the inside out so you keep the look of the boat, then again you could do this ;D ;D.

[NQCairns]

Mark it's hard for me to explain well but basically it is everywhere the transom meets another part of the boat, consider the chopper gun fibers in the boat are only say 10mm long and the woven roving is one of the weakest fabrics in fiberglassing.
The transoms strength may only be born by the first 10mm of any glass forward of it.
So the idea is to spread that 'heavily over a small surface area load' over as many square inches as possible/practical by folding glass from the ply back onto the side/bottom of the boat and when the floor goes in from the floor up onto the transom. I think it is called a fillet.
Something like in the pic in my link below where I was glassing the transverse pieces of ply in around their perimeter. The gunnel also plays an important roll as well. cheers nq

Gav thats a big smile for someone who just spent 40min making itchy dust, or did you find a plastic bag of white power hidden deep in the hull and fall face first into it? ;D.

[markpeta]

Thanks for all the help going to go for it on the inside and cut the floor. Going to look at using the area Cut out for fuel and battery storage to get more room can I do this ?
Also if I cut the floor 400-500mm back what in the way of support beam and stuff do i have to look out for ?

Mark

[blaze]

the floor will be about 12 to 15mm thick, have you a holesaw. drill a couple of test holes to work oout thicknes and if you need to find stringers etc then you can poke a bit of wire through the holes to have a feel about.
cheers
blaze