Transom replacement 1972 16' sportcraft C-Gull

[electric603]

Re: Transom replacement 1972 16' sportcraft C-Gull

A nice day in the sun did the trick. It is all cured. Couple of questions. What is the reason for taking the screws out? How much gap do i need between the wood and the hull sides and bottom?

 

[Bill3434]

Re: Transom replacement 1972 16' sportcraft C-Gull

A nice day in the sun did the trick. It is all cured. Couple of questions. What is the reason for taking the screws out? How much gap do i need between the wood and the hull sides and bottom?

Not sure about the screws, but if you have to take the transom out again, I can see sparks flying. I think no more than a 1/2 inch. I had some spaces small and bigger. I know the bigger the space the more hairy PB you have to use. I swear 5 gal of my resin went to hairy PB. I followed the advice of restorer who wrote a book about it; premix it minus the MEKP. That was a real time saver, when I didn't have anything to do and knew I would need some more I'd just make a large batch and when I was ready it was ready.

 

[jbcurt00]

Re: Transom replacement 1972 16' sportcraft C-Gull

1/4" gap against the hull, large enough to prevent a hard spot, small enough to minimize the amount of filling & filleting material needed

"Fabricating Decks, Stringers, and Transoms"

You can also drill some thru holes in the transom ply, it allows the PB to ooze thru them making an extra mechanical connection, this also minimizes the chance of an air pocket from forming between the transom ply & the hull skin.

It is a minimal risk, but leave the screws & run the risk of having one of them interfere when thru drilling any transom bolt holes: tie downs, transom eyes, motor, swimplatform/ladder, splashwell/bilge drain tubes.......

 

[electric603]

Re: Transom replacement 1972 16' sportcraft C-Gull

Thanks Bill and JB.
I made a new template for the transom. I did not like the way the other one turned out. This time instead of trying to trace the inside of the transom I made the template from the outside. I taped the cardboard to the outside of the transom. Then I traced the outline of the transom. I cut that out then I taped a pen to a piece of wood. When I put it up against the cardboard it set the mark in 1/4". I cut that out and then with some extra trimming it fit into the boat. Then I went around with the pen one more time to get the 1/4" gap to the hull. It still took me close to an hour to make the template but I found it easier than trying to do it from the inside.

 

[Bill3434]

Re: Transom replacement 1972 16' sportcraft C-Gull

Great idea. I was using a compass and a protractor, yours seems to be more accurate. Precision measuring and cutting isn't one of my expertise.

 

[electric603]

Re: Transom replacement 1972 16' sportcraft C-Gull

Thanks. If I had a compass I probably would of used it and never thought of using the wood. What's that saying "necessity is the mother of invention" or something like that.

 

[Bill3434]

Re: Transom replacement 1972 16' sportcraft C-Gull

I think what you are using is more steady.

 

[electric603]

Re: Transom replacement 1972 16' sportcraft C-Gull

I cut the transom out today and some of the pieces I cut off were solidly bonded and some of the pieces I was able to pull apart and there was uncured PB on them. I worried I may have spots of uncured PB in the transom. I can not pull apart the transom but I can't get a good grip on it either. Is there a way to ensure the resin has cured and the transom is solidly glued together?

 

[Bill3434]

Re: Transom replacement 1972 16' sportcraft C-Gull

I cut the transom out today and some of the pieces I cut off were solidly bonded and some of the pieces I was able to pull apart and there was uncured PB on them. I worried I may have spots of uncured PB in the transom. I can not pull apart the transom but I can't get a good grip on it either. Is there a way to ensure the resin has cured and the transom is solidly glued together?

How long hve you let it cured? Get some heat on it.

 

[Woodonglass]

Re: Transom replacement 1972 16' sportcraft C-Gull

Here's the deal, the strength of the transom will come from the tabbing and the full layers of glass to the inside of the hull. If you did a good job of spreading the PB on the entire surface of both sides of the wood then it will be fine. As long as your transom template is within 1/2 " of the Sides and bottom of the hull you'll be fine. You actually don't want a Perfect fit. You need enough space for the PB fillets to prevent Hard Spots on the sides and bottom of the hull.

 

[Bill3434]

Re: Transom replacement 1972 16' sportcraft C-Gull

It definately don't have to be perfect mine sure wasn't. Tabbing wet on wet does wonders.

 

[electric603]

Re: Transom replacement 1972 16' sportcraft C-Gull

I talked to US Composites about the uncured resin and he told me that polyester resin was the wrong thing to use to laminate wood together because it needs air to cure. He said I should have used epoxy. I am thinking about trying to separate the wood grind off the PB and use PL premium.

 

[electric603]

Re: Transom replacement 1972 16' sportcraft C-Gull

I also asked him if applying heat to it would help and he said no.
I didn't spread the PB on both sides as WOG said I only put it on one side.

 

[Woodonglass]

Re: Transom replacement 1972 16' sportcraft C-Gull

WHO did you talk to at USC. Needs AIR to cure??? Are you sure he said that? He also said that heat would not make it set up quicker?? Really???

If you can pull that wood apart, make sure and make a video of it cuz you can be in the movies as SuperMan!!!

PB is totally acceptable for what your are doing. As I stated in my previous post you are Fine! Don't overthink or worry about this so much. Everything you have done so far is totally acceptable.

 

[electric603]

Re: Transom replacement 1972 16' sportcraft C-Gull

Thanks WOG,
I know I'm probably just over worrying but I just want to make sure I'm doing it right and it will be safe. I'm just panicking because I was able to pull some of the scr pieces apart. Should I apply some heat to it or should I just leave it and put it in?
It was a guy named Steve at US Composites. He is some kind of tech there. And I was also surprised to hear him say it needed air to cure because I thought the purpose of the wax in the last layer was to keep air out for a full cure.

 

[Woodonglass]

Re: Transom replacement 1972 16' sportcraft C-Gull

You are absolutely correct. It's called Air Inhibited Laminating resin. Now that it's fully cured, I guarantee you that it will NOT be coming apart. Your were able to pull the cut off scraps apart due to air pockets and the fact it had not fully cured.
You can install it with total confidence now. No Worries!!!!

 

[electric603]

Re: Transom replacement 1972 16' sportcraft C-Gull

Thanks for all your advice WOG. I can stop panicking now.

 

[Bill3434]

Re: Transom replacement 1972 16' sportcraft C-Gull

Thanks WOG,
I know I'm probably just over worrying but I just want to make sure I'm doing it right and it will be safe. I'm just panicking because I was able to pull some of the scr pieces apart. Should I apply some heat to it or should I just leave it and put it in?
It was a guy named Steve at US Composites. He is some kind of tech there. And I was also surprised to hear him say it needed air to cure because I thought the purpose of the wax in the last layer was to keep air out for a full cure.

I don't think the guy has a clue.

 

[electric603]

Re: Transom replacement 1972 16' sportcraft C-Gull

I checked the fit of the transom today and the shape is good but my transom skin is curving out towards the center. The wood is touching on the sides but there is about a 3/8" gap at the bottom toward the center. I'm not sure what to do about it. It is hard to see through to the bottom in the pictures.


I can pull it in at the top but the bottom won't move.

 

[Woodonglass]

Re: Transom replacement 1972 16' sportcraft C-Gull

If you lay a straight edge across the stern on the outside is it flat or curved?