1973 196 rebuild question

[RickK]

I do have scraps left over. So smear the resin in then kind of mush a strip of Coosa into it to fill the remaining void, maybe at a 45 ( plus the Angle of the transom)  angle to the hull and transom to make a curved transition? I think that is what you are talking about. That is what I am going to do.

You should use a 1/4" notch trowel to "butter up" the coosa pieces and then you can stick them where you want. 2 layers, just like the transom core.

[RickK]

If your hull is anything like my 170 hull there was an upward bow of about 1/4" from 3ish" in front of the transom to about 3-4 ft in front.  Was this designed in? Who knows. I filled it in and the boat runs fine. It ran fine with the bow in it too.

[Duffy1470]

Roger that. Over thinking now ceases. My next move will probably be to not think. Grinding/scuffing transom this afternoon. 

What does everyone (Rick) think about using the old liner material as side material for the rear stringer portions I have to rebuild? I have a lot of it, it's free.  My thought was to put Coosa on top of the existing stringers all the way to the transom (and to the bow for that matter to raise deck) then build, using the liner material, the sides of the stingers to the stern. Remember I cut those out. Did a very poor job of it. They are not reusable. Perhaps I should reconsider the the not thinking thing.

[RickK]

You might consider making a mold of the stringers and make enough to fill in the gap(s). If you look at this pic the mold is to the right. Notice I added fillets in the corners of both sides to round out the corners. I added a 1x2 across the ends of the mold to keep it in shape and then I covered the inside of the mold with a cheap painters drop cloth as a quick release.  I rolled drop cloth with resin that wasn't mixed too hot and then laid the 1708 in the mold and rolled resin on it and while still wet, added another layer of cloth. The raw, unfinished stringer that I popped out is to the left. I showed this pic upstream in this thread but it may make more sense to you now.

[RickK]

To the left in the pic is cloth still in the mold and you can see the painters drop cloth too. This isn't rocket science.

[Duffy1470]

Sure enough.  I will do that.

[Duffy1470]

Transom with fillets

[RickK]

 

Transom with fillets

[Duffy1470]

Rick is THE personal boat build trainer. I am copying most of his stuff.

[Duffy1470]

Rick, I am not totally sure I understand what iam looking at in your pic.  Is it two pics or is the stringer popped out sitting next to mold/form? It appears you molded a wing, I assume matching the contour/angle of the hull.

[RickK]

I should have been more clear. The pic is showing 2 molds (at the bottom of the pic you can see the wood of both molds). I popped the new stringer portion out of the right mold and set it so it straddles the two molds. The left mold holds another stringer portion. The resulting stringer needs to be ground down to remove the wrinkles/rough stuff left by the painters drop cloth.

[Duffy1470]

Got it. Crystal clear. If memory serves, you replaced your entire stringers. You did mention you did them in sections which ended up being a pain in the rear to marry/join them. I will be joining the new sections to the old.  I imagine you clean up, make square, the end of the old section and cut the new section to fit between transom and cleaned/squared existing structure?

Unfortunately, when I made the mold I made it an inch short at the top width, 5 inches instead of 6. When I looked at the old stringers, they actually reduced in size to about 5 inches. Either way, I'm going to make these work. Time to get the proverbial hammer out.

When you joined your sections, I assume you feathered the ends out and glassed between them like you were fixing a Crack. I was thinking about glassing a piece of Coosa to the inside of the old stringer under the top and gunnel side to act as a guide. Not the inside/keel side because I stupidly made it the wrong size, an inch short. I may fix the mold, already fileted. Being stupid makes for a difficult life of rework. Just out of curiosity, why ground down the sides of the stringers to remove plastic wrinkles? That an aesthetic thing or glass to new section of stringer thing? Both are valid obviously.

[RickK]

I made 5 or 6 of the pieces, squared them up and I tacked them together with thickened resin, like a glue. I think I cut the last one in half and added it to the 2nd stringer. I ran a string from end to end to make absolutely sure that the stringers were straight, not bowed or twisted.  I used 6" tape (I think) to join the stringer pieces together. Then I ran 2 layers of cloth, 1x1808 and 1x1708 the full length of the stringers, on the outside (hence the grinding) and used epoxy resin, now they were like steel.
Here are the molds - the one on the left is for bulkheads, the one on the right was for the stringers.


Here are the finished stringers, dry fit
https://classicaquasport.com/smf/index.php?topic=10101.msg93388#msg93388

[Duffy1470]

That makes toal sense. I bet they are bullet proof. Can't believe I didn't think, "join them? Grind them." At any rate, i have a couple of pics of the first layers of glass on the transom to post. I learned the following which I think will be helpful to others in the future:
  - a piece of 1708 that is 40 inches long and 25 inches wide takes 2 qts of poly resin maybe a touch more.
  - a novice individual, such as myself, needs one other person to lay 3 of those pieces.
My son helped me. Projects are good.

[Duffy1470]

First layer glass on transom