Fiberglass sizes for deck & transom

[shepinrio]

I'm going to be fiberglassing my deck and trasom soon. I just bought my polyester resin, and was about to buy the fiberglass, but I want to make sure that I'm doing this right. So I will be applying a layer of resin over the plywood on both the deck & transom that I just built, and then will be putting fiberglass on both sides of them. Then I will apply a layer of fiberglass around the wood. Once that is done then I will put the wood down on the deck, and put another coat of fiberglass over the top of the deck to finish it up.

Does this sound right?

Also I'm thinking that I'll be using the 1.5 oz chopped strand mat at least for the top/final layer on the deck. Should I just use the 1.5 oz CSM for the entire process, or would I be better off to use some cloth when I'm covering the plywood (mainly just for waterproofing).

Then once I have the deck done I will be fiberglassing the transom area, and will be following the same process. Is the 1.5 oz CSM the best choice for this or cloth? The boat will be have a 55 HP motor on it, and it is a 14' boat. Thanks for your thoughts.

 

[Greg Mrozinski]

Re: Fiberglass sizes for deck & transom

Welcome to iBoats.

Search the forum here for tons of fiberglass info. Need to get a little more information from you about your boat. Aluminum or fiberglass? How was the existing transom installed?

Here is some quick info:
For your deck you can use the 1.5 CSM on both sides and you will probably be just fine. Some folks on here recommend a light weight cloth instead. The cloth will leave a smoother finish. If your boat is fiberglass then you will need to tab the deck to the hull with something more substansive like 1708 biaxial cloth. I used 1708 tabbing first and then completely covered the top of my deck with 2 oz CSM. If your boat is a tinny then you can skip the tabbing part.

Follow a similar process for the transom. Cover with CSM and then completely cover and tab with 1708. Some folks here recommend multile layers of 1708. In your case probably one would surfice. For a tinny just wrap with CSM to waterproof.

 

[shepinrio]

Re: Fiberglass sizes for deck & transom

Thanks Greg. Yeah it is a fiberglass boat. The original transom looked like it had been just fiberglassed on in a couple of layers. Hard to say because of a lot of it had rotted before I got it. So did you do use the biaxial cloth to cover the entire first layer and tabbed to the hull or just tabbed to the hull and, and then covered with the 2 oz csm?

Or would I also be able to coat the plywood with cloth, and then cover the entire deck with a biaxial cloth layer as I tab it to the hull?

Not to sound cheap, but I've got a pretty limited budget, but I also want it to be done right, so I'm trying to find the most inexpensive, yet best way to do this so I don't have to redo it hopefully for a long time.

 

[Greg Mrozinski]

Re: Fiberglass sizes for deck & transom

Shep,

You can do it pretty much anyway you want. If you want to keep the price down (I don't blame you) use the 1708 for structural stuff like tabbing and joints. The CSM will add stiffness and mainly water protection. No need to use 1708 on your deck. Just for tabbing. If you decide to use a 6-10oz cloth on your deck you will need to use the CSM first since cloth adheres better to CSM. Most 1708 comes with a layer of CSM on one side already so no real need to use CSM first.

For my boat I installed the transom first and then the deck. I constructed the transom out of two pieces of exterior 3/4" ply glued together with PL premium. I then glued the transom to the outerskin and filleted with PL. Once that was completely set-up (at least 72 hrs), I coated the transom with poly resin. While the resin was still tacky, I covered it with 2 oz CSM (I had 2 oz CSM already. 1.5 oz would also be fine) and resin. I also extended the CSM out onto the hull sides and bottom about 12". I then followed with an entire layer of 1708 and resin on the transom and hull sides and bottom just like the CSM.

For the deck, I covered the underneath side of the deck with poly resin and CSM. I installed the deck and gave it a coat of resin. I then filleted the deck hull joint with a thickened poly resin mixture. I then tabbed the deck to the hull and transom with a 12'' strip of 1708. After that I covered the entire top of the deck (including the tabbing) with the CSM.

Post some pics. Make sure you use un-waxed resin. Check out my resto thread for some pics.