77 Crestliner transom replacement advice

[Patfromny]

Hello all I am a newbie so please be patient. I have a 77 Crestliner Nordic 16 16 ft aluminium v hull bow rider. It has been in the family since it was new and has been left upstate at a fishing lake. We replaced the floors and some seat backs within the first few years because AMF decided particle board would work in a marine environment
I realized the boat needed a transom so I dragged it home and toke it apart. I found more questionable design choices. I was shocked when I saw how small the transom is. It is 65 inches long but only 6 inches wide and only 1 1/4 inches thick. I guess (hope) the boats metal structure takes most of the load. In addition the design of the back of the boat is such that all the water runs down the boat under the end caps and just runs into the boat onto the transom. I'm surprised it lasted more then a few years. sorry no pics but this is my first post. baby steps.
My question to the experts here is; since the transom is roughly the size of a 2x6 could I just use a planed down 2x6? Meaning I would take 1/2 inch off the thickness. I would still resin it and fiberglass it if recomended. I am mechanically inclined and am adept with hammer and saw. I am just a boat repair novice since this boat has been relatively painless over the years. I apologize for my long windedness... I've had the desease my whole life. Thanks in advance guys I look forward to reading the forthcoming suggestions.

 

[Lyle29464]

Re: 77 Crestliner transom replacement advice

I would need to see a picture. I am lost on the 2x6 thingee.

 

[jbcurt00]

Re: 77 Crestliner transom replacement advice

A plywood lamination totaling 1.25" by 6" wide would be structurally stronger then a 2X6 planed down to 1.25" that's only 5.5". IMHO

But yes, pix are always helpful

Welcome to the iboats dry dock...

 

[64osby]

Re: 77 Crestliner transom replacement advice

Plywood is stronger than plank wood given the same thickness. plywood is also less inclined to split over time. Using a plank board instead of plywood is a personal choice and part of the info needed is what size motor are you running and what is the motor size capacity for the boat.

I cut down a piece of old douglas fir 2 x 8 for my 14' Lone Star, it has an 18hp max and it is very strong and works well for me.

 

[jigngrub]

Re: 77 Crestliner transom replacement advice

2 pieces of 5/8" plywood laminated together would be your best and strongest build.

You can seal the plywood with several coats of exterior grade spar urethane or a good exterior porch and deck paint, a quart of either should do the job well.

 

[Yacht Dr.]

Re: 77 Crestliner transom replacement advice

What is the actual thickness that you want to achieve ? 1.5 total thickness .. or is it under or over ?

Two .5" lams of MG will give you 1" .. plus the glass will give you 1.5 ish.

Or you could do it with 5/8" like Grub suggested .. then an 1/8" of glass would cover that.

YD.

 

[Patfromny]

Re: 77 Crestliner transom replacement advice

Sorry about the no pics. the boat is stuffed in my garage next to another project and it is hard to get good pics with the limited space. I will drag it out over the weekend and take a few. The total thickness is 1.25 inches by 65 inches long and is 6 inches from top to bottom. It was made of plywood but it looked like a 65 inch 2 x 6 when I took it out (if it were in one piece). I think I'm leaning more toward resin and glass. I think that is the best long term right? I had to cut about 50 rivets and take most of the back tub out to extract the transom. I don't want to ever do this again. I have a 35hp Evinrude on it now but am looking for a 40hp(40 max rule on lake). the max hp rating for the boat is a 90hp.
If I were to use resin and fiberglass should I use smaller stock plywood? I have a few other questions related to this repair. should I start new threads or ask on this one? outer transom questions etc.

 

[jigngrub]

Re: 77 Crestliner transom replacement advice

Keep all of your questions in this thread, it makes it easier to keep track of and the site mods prefer it that way.

It depends on who you talk to as to what the best sealer is, fiberglass and resin is good for fiberglass boats but epoxy resin by itself is the best sealer for wood going into an aluminum boat IMO. You can also mix a powder filler with the epoxy resin and make an epoxy adhesive for laminating the 2 pieces of plywood together. 4 coats of epoxy resin makes a very strong barrier between your wood and the elements.

This is what one of my deck pieces looked like after 4 coats of epoxy resin:

 

[Yacht Dr.]

Re: 77 Crestliner transom replacement advice

Yes I would use a smaller stock of ply and build up with glass.

Im assuming you still want that larger plant on there ..

YD.

 

[Patfromny]

Re: 77 Crestliner transom replacement advice

Thanks alot guys. I appreciate the info a great deal. Nice looking floor boards jigngrub. Thanks for the powder tip. I'm gonna do the floors too while I have it home. we replaced them years ago but didn't coat them. I figured I'd buy a gallon of epoxy and do it all at once. I will also replace the floatation foam. I have pictures of the boat when new and it was sitting ALOT higher in the water then. Must have several hundred pounds of water soaked in. I'll ask about that when I get to it lol.
I don't want the bigger motor Yacht Dr. I need the bigger motor. The boat is known on the lake as "The Tug Boat". slow and loud. I'd even consider putting a 50 on her and put 40 labels on:wink:.
My next of many questions is about the outer transom. I was wondering if I can epoxy and glass that too or just epoxy? It is very close to the water line. I would also like to paint it (outer trans) and was wondering what type of paint I could use and the prep steps to take if I epoxy. I own an hvlp so any type of paint is doable. Thanks again you guys are saving me alot of research as well as trial and error. BTW I am sorry if my writing is choppy...I am using a loaner laptop till mine is repaired and it doesn't have a comma button. real annoying but pretty funny

 

[jbcurt00]

Re: 77 Crestliner transom replacement advice

Loose some water weight & it may make the 40 ample enough.....

 

[jigngrub]

Re: 77 Crestliner transom replacement advice

All you need for all of your wood is epoxy resin and then paint over it for UV protection, Rustoleum makes a good oil based marine paint.

You'll be surprised at how much faster that boat will run with the same motor when you get all of that soggy old foam out of there and replace it with new and dry foam.

Make sure your decking is good and dry before applying the epoxy resin, any moisture that's in there will be trapped after the epoxy goes on.

 

[Patfromny]

Re: 77 Crestliner transom replacement advice

I hope so jb. I'm not really much of a diviant anyway. Also I store the boat with the lake owners so... I hope you're right.
Jigngrub I will replace the wood with new. Should I dry that out somehow or will it be dry enough? The 35hp motor is way to small for this boat. It always has been. The boat weighs 800lbs I think unladen. put my 200lbs in and the weight of the motor and you have 20mph on a good day. put someone else in and it's 16mph at very best. Would like to maybe teach my daughter to ski behind it with a 40. The difference from 35 to 40 is like small block/ big block I'm told. a 35 is a supped up 25 were the 40 is a detuned 50 or 60(evinrude) over simplified I'm sure but not too far off the mark?

 

[series60]

Re: 77 Crestliner transom replacement advice

Hello all I am a newbie so please be patient. I have a 77 Crestliner Nordic 16 16 ft aluminium v hull bow rider. It has been in the family since it was new and has been left upstate at a fishing lake. We replaced the floors and some seat backs within the first few years because AMF decided particle board would work in a marine environment
I realized the boat needed a transom so I dragged it home and toke it apart. I found more questionable design choices. I was shocked when I saw how small the transom is. It is 65 inches long but only 6 inches wide and only 1 1/4 inches thick. I guess (hope) the boats metal structure takes most of the load. In addition the design of the back of the boat is such that all the water runs down the boat under the end caps and just runs into the boat onto the transom. I'm surprised it lasted more then a few years. sorry no pics but this is my first post. baby steps.
My question to the experts here is; since the transom is roughly the size of a 2x6 could I just use a planed down 2x6? Meaning I would take 1/2 inch off the thickness. I would still resin it and fiberglass it if recomended. I am mechanically inclined and am adept with hammer and saw. I am just a boat repair novice since this boat has been relatively painless over the years. I apologize for my long windedness... I've had the desease my whole life. Thanks in advance guys I look forward to reading the forthcoming suggestions.

Here is what I did when I had to replace my transom. Much larger boat but the principle is the same.
1984 IMP X215SC Rebuild Page 5

 

[Patfromny]

Re: 77 Crestliner transom replacement advice

I have to say 60 that is very cool. It would also be the smallest parts list I ever took to Depot. I do have a few questions: Does your vacuum still work after leaving it on for four hours? This process forgoes any clamping? Did you have any problems with the plastic sticking to the boards? Where do you get the seam sealer? I'm asking because whenever I work on my stuff my last name Becomes Murphy. Everything seems to go wrong. I would probably need to make three spare bags-at least three vacs and a spare garage to start. Oh and five friends...just in case. lol Thanks for the link it looks great.

 

[series60]

Re: 77 Crestliner transom replacement advice

I have to say 60 that is very cool. It would also be the smallest parts list I ever took to Depot. I do have a few questions:

Does your vacuum still work after leaving it on for four hours?

Yes it's still working. These shop vacs are not effected by running for long periods. I got the idea from my chemist friend where I buy my epoxy.

This process forgoes any clamping?

As I mentioned in my write up, I did use a few wooden 3/8 dowels to keep the two plys in position but no clamps or screws. The holes the dowels fit into where slightly larger then the dowels to allow movement between the plys and allow the epoxy to flow out.

Did you have any problems with the plastic sticking to the boards?

Plastic doesn't stick to epoxy much. Lets say it will stick but pulls right off if it is heaver plastic. Don't use those thin grocery bags because when they stick the plastic tears apart making it more difficult to remove. I use the heaver stuff to protect things I don't want epoxy on. If you set your work on plastic it will leave a impression. I make plastic booties for my shoes so I don't track sticky into the house. Yeh I can be a real messy guy sometimes.

Where do you get the seam sealer?

The seam sealer was purchased from my epoxy guy but it is the same stuff RV manufactures used to seal their windows and doors. It is a grey pliable material that comes in a roll and can usually be found at RV parts stores. Never knew what the name of the stuff was but I will ask. It's just press and stick with some pressure between the sheets of plastic. Comes right off when done.

Good luck.