Nitro 170 transom rebuild and questions???

[boat86fish]

Hello all,
I am in the possess of replacing the transom on my 95 nitro 170DC. Here is my progress so far. I'm going to have questions as I go along here. Any help is greatly appreciated.

I got the top off today. I had to cut the floor a little more than I wanted to. The floor is in good shape so I think I will fiber glass the cuts back together if that's advisable. The only fatality was the splashwell. It was glued to the transom so I had to cut around it. I Hated to do that.
It took my Dad and I around 4 hours to pull it. Other than the floor and splashwell it isn't to bad.

I peeled away some of the fiber glass to expose the wood. Looks like only a single layer of fiberglass. The wood is soaked all the way through, water would come out when squeezed. There are a couple rot spots at the corners. The foam is water logged too. The areas where the factory injected foam were not sealed allowing water right into everything.

I had to cut the splashwell to get the top off. All the prying and chiseling didn't budge it. There is a thicker area of fiberglass between the what I cut and the transom. I guess I'll have to build that back up, I guess I'll worry about that later. Any pointers would be great.

The hull....

I'll be posting plenty of pictures as I go on.

 

[Woodonglass]

Welcome to iBoats! Pretty typical!! If you use a circular saw set to a depth just shy of the depth of the wood in the transom and cut the transom wood in a 1" grid pattern It'll be real easy to use a wood chisel to remove the wood from the glass skin. Have you core sampled your stringers??

 

[boat86fish]

Thanks! I haven't checked the stringers yet, that will be the project for this week. When tapping on that area with a hammer I get a dull thunk. No doubt they will need replacing.

 

[Woodonglass]

Yeah, and since you've got her down this far you might as well do it all and make sure she's NEW Thru and Thru. That way you'll KNOW she'll be Good to Go for several decades!!! Let us know if you need anything!!! This Link should have some helpful info for you when the time comes....Fabricating Decks, Stringers, and Transoms

 

[studioq]

It really, really helped me to work my way through the transom in smaller chunks. The guy in me wanted to pry it out in one piece.. Not gonna happen..
Sawing down and across in a grid will really make things move along after the edges of the glass are cut.. After I had the top out - the bottom finally broke freee and came out.

 

[boat86fish]

I finally got around to doing more work on the boat tonight and got transom out, thankfully in one piece so I have a template for the new one. I pulled lots of soaked foam out.

This thing does not have any stringers. It looks like just fiberglass ox with wood on top. I'm going to see if I can fabricate some stringers for extra strength.

Now to figure out how much stuff I need. I'm planning on using uscomposites epoxy resin and 1708 cloth for most of the work. The transom wood Im still trying to decide. Coosaboard is out of the budget. I'm thinking of either exterior grade plywood or marine grade.

 

[Rickmerrill]

If you are going to use epoxy you want to use 1700 biax not 1708. You don't want or need the CSM on the back. If you're interested here is a post with a little more background on this subject.

http://forums.iboats.com/forum/boat...t-inside-hull-overlay-woven-biaxial-questions

 

[Woodonglass]

Yup, you have a tub foamed hull If the foam is dry then you are a lucky boater. As stated no CSM needed just Biax with Epoxy. Poly Resin will work just fine too and save you some bucks as well as working time. Totally up to you.

 

[boat86fish]

I've really gone back and forth between poly or epoxy. Epoxy is stronger and more forgiving for me an amateur at this. Poly would save me money. I do have some wet foam under the floor, I'll cut forward till its dry the build back.

 

[Woodonglass]

More Forgiving???

 

[boat86fish]

Well maybe I was thinking easier to mix. I'm going to use epoxy since its stronger.

 

[boat86fish]

Thanks Rickmerril that helped. I'm not looking to use more epoxy then necessary, expensive stuff. Although the 17oz biax is more expensive then the 1708?!?! That's from uscomposites. wonder why that is. I hope I'm looking at the right stuff. DB170 is the part number.

 

[Rickmerrill]

Yes, DB170 is correct. Actually I think you were looking at the 38" 1708, the 50" 1708 is 8.50 and the 50" DBM170 no-mat is 7.95. Just saved .55 per yard!

 

[studioq]

More Forgiving???

Yep - that wouldn't have been my first choice of words either.

 

[boat86fish]

I did a little more demolition tonight as I had some time an hand.

I still have some damp foam under the floatation boxes. I dug out as much as I could but what is left is a little damp still. I am wondering if I can try to dig more out then put a fan on it for a couple days. Otherwise I will have to cut the whole area out and redo it.

 

[Arawak]

Good progress!

From what I have seen, foam that will hold water has become like a sponge. You can dry it out but as soon as it gets wet it will suck it back in. IMO best to get it all out if you can.

 

[boat86fish]

It's back to work on the boat now. I got the grinding on the hull done today. Man that's a nasty job. here is the progress.

Just for kicks I set the old transom in the boat to see the fit and wow, either it shrunk something cause I've got nearly one inch gaps on either side. Looks like I'm going to need to widen the new one a bit. Any thoughts on this??

I got my fiberglass and epoxy in I'll be laminating the transom when I get some free time.

 

[boat86fish]

I got my transom pieces cut out today. I have a question...Should I put a layer of 17oz biax cloth between the two halves or will I be ok with out it?

 

[Woodonglass]

I think if you use TiteBond III and wood screws ever 4" to cinch em together it'll be all that's required. TBIII cures to be 100% waterproof and super strong. Remove the screws the next day and the PB will fill the holes when you install the transom.

 

[boat86fish]

I am wondering about the structural integrity of titebond III. It wood help keep cost down, but I won't want it to fail.