1971 20 SF Transom project

[strick]

Looked back at he post. Sorry my bad... I thought you were talking about using doug fir planks for the transom. Your choice on transom material depends on how much you want to spend and if you are worried about a little extra weight and water intrussion. The transom's in these boats were made of plywood and they lasted 30 years. So if you re do it properly with plywood then the transom should last another 30 years. The main thing is like Bobby said you have to pay special attention every time you drill a hole in the back of your boat that you take precautions to keep the water out of the wood. I re-did my transom with plywood. It may be a little on the heavy side but it's solid. I may try that coosa board on the next transom I do....seems that is what everyone is doing these days. It is 30% percent lighter then plywood which is not really all that much weight difference if you are just re-doing the transom... if you are redoing the entire boat then it adds up.

strick

[Yamtt125]

Will, thanks for the advice about the grinder. Tonight I just sanded out the small particles of wood the were embedded in the resin they used when the boat was made.

Wart, thanks for the information reguarding the wood. I'm iehter gonna use the regular dougfir, or the marine grade. Like strick said, if the origional lasted 30 yrs, then the new one should too. And I will deff be happy if the new one last another 30 yrs. If you think about it, in another 30 yrs, the boat will prob need another major facelift anyways, so I don't see too many advantages with going with coosa anyways.

Grady,
After seeing you start your project, It deff gave me the motivation to move a little quicker than i was before. Yours is coming along great. How do you like the results of the fairing compound you used?? I have to decied on what kind I'm going to be using for my floor and other things.
I'm deffinately gonna use trayders and marks boats as guides.

How smooth or rough should I leave the transom? Right now i'm using 60 grit paper with the orbital. Hopefully tomorrow I will finish up the sanding, and chissel away the small amount of the old cabosil mixture.

Thanks for all the responces. Tomorrow I will post new pics of the transom.
-andrew

[GradySailfish]

Hey Yam...your project is looking great. I like the grinder Strick showed....those work great on my DeWalt 4.5 inch grinder...much better then a simple disk...only drawback is they're slightly more expensive.

I would not leave any surface which is expected to get resin on it smooth. Rough up everything as it increases surface area which intern increases adhesion.

The fairing compund I used was Interlux Interfil 830. It worked out great...it spreads and sands really nice. After I glass over the deck I basically "skim coated" the entire deck with fairing compound.

-Alex

[Yamtt125]

Unfortionately, I woke up to rain this mornin so I will have to finish chisseling the old cabosil mixture on Monday b/c i'm going to vermont for the weekend.

So far, this is what the entire transome looks like right now. The wood looks dark b/c it is wet from the rain, but there isn't that much left to take off.



Adios
-andrew

[Yamtt125]

Have today and tomorrow off from work, so I went to the lumber yard and picked up 2 sheets of marine ply. They charged me 92.00 per sheet. Other yards around had similar prices so i figured it wasn't too steep. Also, got all my fiberglass supplys from LBI in groton CT. I have to say, there website is very easy to understand if your a novice in buying fiberglass.

I just have a couple last minute questions before I start to lay it up....I plan on building up the outer skin with a couple layers of glass, and I would to know whether or not I have to wait for each layer to cure completely, or can I just wait an hour or so to lay the next on?
Here is my plan for the transom...

outerskin
1.5 oz mat
1708
1708
wood
1.5 oz mat
wood
1.5 oz mat
24 oz woven
1708
6oz cloth

Am I going overboard with all the layers of glass, or should I have more?....all opinions welcome. Thanks

[Greene]

I'd use 2 layers of 1.5 oz mat for laminating the two pieces of plywood. Make sure they are both wet.

I'd also use some more mat over the 1708 before the final 6 oz cloth layer. If not you'll end up with print-thru of the 1708 pattern.

[Yamtt125]

Would it make any difference if the last four layers were as follows:
1.5
1708
24 oz
6 oz
Thanks for the reply

[WillyC]

Are you using epoxy or polyester based resins?

[Greene]

You wrote outside skin in your post...you meant inside skin, right?

I would use more 1708 on the inner skin. But any combo you use (like the one you suggested) is going to be very strong.

[Yamtt125]

I am using polyester laminating resins.

I mean inside skin of the transom...sorry about the confusion. Thanks

Greene, are you the same Greene some the cm site?
If so, I used your transom job as sort of a template because raybo had alot of input in it.
If you remember, How much resin did you use?
Hows your transom holding up anyways???
Do you have any advice on what NOT to do? Thanks
-Andrew