Transom skin thickness

S

sam03v

Cadet
Joined
May 10, 2006
Messages
27
I have a early 70's fiberglass 14.5 foot boat. Nothing fancy, just a v-bottom fishing boat with a tiller outboard. I bought it for $200 just for the trailer and then decided to rebuild the motor(35 johnson) and boat. The stern and transom were in bad shape so I literally cut the stern off using a sawsall. The boat is a little shorter now :). I've fiberglassed a new outer skin on the stern, but I am not sure how thick to make it. Right now it's about an 1/8" thick. I plan on putting a 1.5" thick plywood transom on the inside and then glass that it in. I've put in a new stringer (there was only one down the keel) and I will be installing a new floor too.

My question is how thick should the transom outer fiberglass skin be? The sides of the hull are about 1/4" thick solid fiberglass. I'm hoping I don't have to make it that thick. And I threw away the old skin awhile ago so I dont' have any reference.

Any comments (or slaps to the head) would be greatly appreciated.

sam
 
S

sdunt

Petty Officer 1st Class
Joined
Sep 11, 2005
Messages
389
Re: Transom skin thickness

You're in the right ball park.. If I recall correctly, my boats outer skin is about 3/16 of an inch thick. The 1 1/2 inch wooden transom is doing the work.

Read my share a project blog, in my signature, it might give you some ideas on process, etc. You can also search share a project for other transom jobs and see what other folks did as well.
 
A

andy6374

Lieutenant Commander
Joined
Aug 4, 2005
Messages
1,617
Re: Transom skin thickness

1/4" inside skin, 1/4" outside skin. Make sure the outer skin wrap under and around the hull. Same thing for the inner skin, that is make sure it laps onto the hullsides and bilge. It's best to do it in increasing overlapping sizes, like 2", 4", 6", 8".

The skins are where the real strength of the transom lies. The wood is to keep to glass from warping under stress/force.
 
S

sam03v

Cadet
Joined
May 10, 2006
Messages
27
Re: Transom skin thickness

Okay, I'll go with 1/4" for both. Guess I'll have to make another trip to the marine shop to get more fiberglass/resin.

Thanks!
 
B

BillP

Captain
Joined
Aug 10, 2002
Messages
3,290
Re: Transom skin thickness

sam03v said:
I have a early 70's fiberglass 14.5 foot boat. Nothing fancy, just a v-bottom fishing boat with a tiller outboard. I bought it for $200 just for the trailer and then decided to rebuild the motor(35 johnson) and boat. The stern and transom were in bad shape so I literally cut the stern off using a sawsall. The boat is a little shorter now :). I've fiberglassed a new outer skin on the stern, but I am not sure how thick to make it. Right now it's about an 1/8" thick. I plan on putting a 1.5" thick plywood transom on the inside and then glass that it in. I've put in a new stringer (there was only one down the keel) and I will be installing a new floor too.

My question is how thick should the transom outer fiberglass skin be? The sides of the hull are about 1/4" thick solid fiberglass. I'm hoping I don't have to make it that thick. And I threw away the old skin awhile ago so I dont' have any reference.

Any comments (or slaps to the head) would be greatly appreciated.

sam
Click to expand...

1/8"-3/16" is normal for transom skins on most 14' -18's. The strength is in the plywood and side tabing where glassed to the hull. Everywhere else on the transom is for ding protection and waterproofing.

bp
 
S

sam03v

Cadet
Joined
May 10, 2006
Messages
27
Re: Transom skin thickness

Alright, I'm going with the Commander's advice. One more layer of woven, mat and cloth and I'm calling it good. That'll add another 1/10th of an inch to the outer skin. Then on to the plywood and inner skin....
 
You must log in or register to reply here.
Top