Transom Glassing Opinions??

[76SeaRay]

I bonded together two layers of 3/4 inch marine plywood using Titebond III. Since I don't have much experience with fiberglass, I had a guy with lots of experience with boat fiberglassing and lots of recommendations glass in the transom wood. Given what I have read here, I am wondering if there is enough tabbing. So the following are pictures of the transom and the transom layering. It measures out as 2.06 inches thick around the keyhole slot. Looking for opinions on the tabbing and if I should add more tabbing with another layer of fiberglass on top. I have just less than 1/4 inch for anymore build up. He used polyester resin.

 

[todhunter]

I'll let the pros answer, but it looks pretty good to me....I dont think I would worry about it.

 

[76SeaRay]

Bump, anyone else have input on this glassing?

Thanks...

 

[GA_Boater]

You don't need to tab all the way to the keyhole, only the edges to the hull. How many layers of cloth have been tabbed? It looks like only one layer.

2"- 2.25" is the transom thickness spec and no more than 1/8" variance in the clamping area around the keyhole. When you're laying more cloth, coat the keyhole edges with resin. Dab some in the bolt holes if you can without blocking the holes. Raw edges and holes are where most rot begins, so resin and 5200 during hardware installation together offer a bit more protection.

A suggestion - Put a space between pics so they don't run together. I was about to say the keyhole looks slanted with the run into the pic above.

 

[76SeaRay]

I think the reason the keyhole looks slanted is the camera angle. I drilled and cut the keyhole using the actual Mercruiser metal drill template.. Based upon your comments it sounds like I should add additional tabbing all the way around and another layer of cloth to the entire transom... It looks to me like only one layer of cloth as well, hence my asking for opinions here..

Sorry, forgot the pic spacing doesn't come out right if you upload more than one at a time...

 

[sphelps]

Hard to tell but with poly resin you must use CSM before the cloth wet on wet for a good bond . Looks like its just a layer of woven ... So if using woven cloth it goes csm then woven another layer csm then woven .. If 1708 Bi-axle was used it would be ok ... It has a layer of csm sewn to it already ..

 

[Woodonglass]

Good call Sam! I’d be more comfortable if you applied 1 layer of 1708 and extend 6” over what’s there

 

[76SeaRay]

Thanks guys. I wasn't overly comfortable with the way it is after I got it back... Should I tab over what is there all the way around the sides and then cover over the entire transom with 1708 with the 6 inch overlap as you point out or just go 1708 over all?

 

[Woodonglass]

Thanks guys. I wasn't overly comfortable with the way it is after I got it back... Should I tab over what is there all the way around the sides and then cover over the entire transom with 1708 with the 6 inch overlap as you point out or just go 1708 over all?

I would

 

[76SeaRay]

Thanks again, will do...

 

[mickyryan]

I would agree id go out a lil further on tabbing

 

[76SeaRay]

Thanks, I am assuming I can use 1708 for the additional tabbing as well as overall cover. Also, this polyester has been on there for about 3 months so I am assuming I need to sand it to apply another layer? Would it be better to use epoxy over the polyester or would that be overkill?

 

[mickyryan]

Just sand wipe down with alcetone and do the deed

 

[JASinIL2006]

If you wanted to get really picky, you could rough up the existing fiberglass with some sandpaper, but a good washdown with acetone would be sufficient.

 

[76SeaRay]

My 1708 will be delivered mid next week. I have polyester resin in both laminating and finishing. I plan to gelcoat the transom in white to make it lighter in the engine bay when working on it in the future. So, if I understand the process correctly, I use the laminating resin for everything and then wax in the last gelcoat layer. If I don't gelcoat, I assume I use laminating resin on the extra tabbing and then use finishing resin with the 1708 final layer over all?

Thanks...

 

[JASinIL2006]

For the gelcoat process, you are spot on.

I'm not familiar with 'finishing resin' - I use US Composites laminating resin for my entire project. What exactly is finishing resin?

 

[todhunter]

For the gelcoat process, you are spot on.

I'm not familiar with 'finishing resin' - I use US Composites laminating resin for my entire project. What exactly is finishing resin?

It already has the wax additive in it.

 

[76SeaRay]

So I got delayed on doing this work but things are warming up now and I got a little experience with polyester resin on filling a couple of speaker holes. Ready to add the tabbing and a layer of 1708 to the entire transom. My transom thickness measures out at 2.020 so I am assuming that one additional layer of 1708 will still come out less than 2.25 max for the Alpha One.

It appears the fabric used for the current glassing is woven roving. I have a question on applying the 1708, should the CSM side go towards the woven roving on the transom with the mesh out or the mesh towards the transom with the CSM out?

Thanks.

 

[88 Capri (2022 SOTY)]

The CSM should face down on the 1708.

 

[todhunter]

From my measurements on my boat, one layer of 1708 hand laid adds ~0.050" thickness. Agree with the above statement - CSM down.