Center stringer? Do I need it?

[GaJeff]

Re: Center stringer? Do I need it?



finally some pics....i got a whole lot more. this is just some of the hull, stringers, transom, and the foam at the bow.

 

[GaJeff]

Re: Center stringer? Do I need it?



These are the pics of the fuel tank that i want to install. the smaller one is 19.5gal and the larger one is supposed to be 50gal. Now im not completely sure if it is 50gal because it doesnt have a label or manufactures tag. This tank was custom built for a 25' Well Craft with 2 350 chey engines and Alpha 1 drives. that vessel had 2 tanks and i got one. The boat had a wreck and completely tore the keel out and it was parted out.

more pics coming

 

[Woodonglass]

Re: Center stringer? Do I need it?

Based on your pics I believe you could do away with the center stringer build a ski locker and install the tank as you wish to do. I would advise to install some lateral bulkheads but other than that the design should be viable and sound.

 

[GaJeff]

Re: Center stringer? Do I need it?



This is the front bow foot well. It has that foam sprayed on the under side of it. I really dont think its going back in. Im going to make the front well out of 1/2'' wood and glass it up. I would rather have it so when your sitting in the bow your feet will be on the deck instead of in this well. There was a 4-6'' gap from the deck to this well and it bowed in when stepping on it. Its cracked anyways from years of stepping there, I am going to need some type of foam to put back. i think the 2 part foam would be best in the bow.

The other piece is the transom section of the top cap. It has a little foam on it. Most of the foam was sprayed under the cap and none was put under the floor. Where would I get the spray type foam from and would it be a good choice?

 

[GaJeff]

Re: Center stringer? Do I need it?



This is my transom that i have built. It measures 2'' with it mounted to the back of the boat. I got enough woven roving to do the transom from River Supply. I talked to a few people about the quadaxial and was advised not to use it. First its not going to lay down like Im going to need it to and second i was told that a few smaller layers would be stronger than one giant layer. Its some heavy stuff but its more for flat surfaces or curved along a wide spread. So Im just going to do it like everyone else. I built my transom as Woodonglass suggested in his thread so i have to mix up some PB and fill in all the screw holes before glassing.

Thats fine with me as I need a break from glass grinding.....Boat building sucks when it seems all your doing is grinding and itching. Im a metal fabricator so the grinding isnt the issue its the ITCHING FOR DAYS that sucks. Oh well its part of it. I bought a few suits so hopefully I'll be done here shortly.

 

[mwe-maxxowner]

Re: Center stringer? Do I need it?

I swear eventually you build up a tolerance to the itching.

 

[GaJeff]

Re: Center stringer? Do I need it?

Well I'm going to the shop tonight to sand down the PB and glass up the transom before I install it. Should I glass both sides or just the outside and resin up the back side? Tomorrow after everything has cured I'll be installing the transom for the last time.

Jeff

 

[Woodonglass]

Re: Center stringer? Do I need it?

How thick is the outer skin of your boat? Most outdrives require the finished transom thickness to be no more than 2 1/4" If it's 2" now and with the PB and the outer skin you don't have much to play with for the inside laminations.

 

[GaJeff]

Re: Center stringer? Do I need it?

It's 3/8" the 2" is the transom plus the outer skin. The completed transom without glass is 1 5/8". I figure I should be rite where I need to be after its installed and the inner skin is on.

 

[Woodonglass]

Re: Center stringer? Do I need it?

Ok, Kool, just checkin!!!!!

 

[GaJeff]

Re: Center stringer? Do I need it?

My wife sells pools and spas and the plaza that the building is in stays open till 9pm. Who buys pools and chemicals at 9 at night? Anyways since I dont have a sitter for my boy I dont get to go to the shop until she gets home, which makes for late working and slow progress during the weekend. Oh well.... by the time i get home during the week my son is usually asleep so Id rather hang out with him anyways. Hopefully he will be able to help me in a few years.


This is what I got done last night. Sanded down the PB in the screw holes and smoothed out the fillets. Since this is my first time making the PB there is a bit of a learning curve on how to spread it. I made it a little to thick and it was extremely difficult to spread for the fillets. It was more like a putty.

This is the first layer of glass on the transom and Im going to install it tonight.

View attachment 204225View attachment 204226View attachment 204227View attachment 204228

 

[Georgesalmon]

Re: Center stringer? Do I need it?

thats 24oz woven roving. That's what thousands of boats were made with before all the stitched materials like 1708 were born. You'll need some 1.5oz CSM if your going to use that. When I did my stringers I used 2415 which is a 24oz woven roving with an 1.5oz mat attached. I used two layers and was able to laminate around a 3/4" plywood with rounded edges. Wasn't easy but with some good rollers it worked dandy ( I used it because it was a free leftover from a Navy boat project)

I might reconsider a small center stringer. Not for strength in the water. I'm thinking that depending on what kind of trailer you have if there are center rollers with a lot of pressure on the hull center you could have a problem.

 

[GaJeff]

Re: Center stringer? Do I need it?

Thanks for all the advice. I have decided to remove the center stringer and beef up the 2 outer ones and buildup the 2 outside of those so they will touch the deck. I will be installing the fuel tank below deck and foaming around it. I will add bulkheads before and after the tank, and one more between the windshield. When I build my engine box I think it would be a good idea to make it strong enough for a v8 although it will probably only get a 4.3 v6.

I've installed my transom and now waiting for it to cure. It's time to start on the stringers. What is the best wood to use? It had boards in there but I've seen many builds with laminated ply for thickness. Should I go back with what was in there or laminate the ply?

 

[Woodonglass]

Re: Center stringer? Do I need it?

Plywood. It's stronger!

 

[GaJeff]

Re: Center stringer? Do I need it?

If I used ply should I sister them together for the length or break them up in sections with a bulkhead or something dividing them?

 

[Woodonglass]

Re: Center stringer? Do I need it?

I'd use 1/2" Ply and over lap two layers to achieve the lengths I needed. Use Titebond III wood glue and screws to laminate them together. Always have at least a 24" overlap.

 

[GaJeff]

Re: Center stringer? Do I need it?

Ahhhhhhhhh... I see. That would make it way easier that sister joints. Is this common practice? Ill be working on this later this evening. Thanks for the tip.

Jeff

 

[Woodonglass]

Re: Center stringer? Do I need it?

Yep, pretty common.

 

[jbcurt00]

Re: Center stringer? Do I need it?

Quite a few have used the lap joint layout WOG posted. Some used 3/8" ply X2 to get 3/4" stringers thru 3/4" ply X2 to get 1.5" stringers. All depends on what thickness they needed.

 

[GaJeff]

Re: Center stringer? Do I need it?

What's the difference between tooling, mold making, and the regular glass that we use? Like csm 1708 woven roving? Is all glass about the same except for its weight? Or are they specific?