More Stringer info Please!

[sleekcraft26]

Hi,

I am in the process of rebuilding an '82 Sleekcraft Ambassador. It has a fiberglass hull. As I got the boat it has only the engine stringers and the bow bulkheads left inside. Everything else has been cut out. I am planning to replace the original wooden stringers with wood. (I have parts of the old ones for a template) I am looking for some specific recommendations as to what type of fiberglass mat and resins I should use and where the cheapest place to buy them is. Obviously I will be putting a floor back in it as well. Any help would be greatly appreciated. While I am a newbie to boat repair i have done a fair bit of fiberglass repair as well as built a number o0f cars and trucks, so I am not totally clueless. I am planning on using doug fir for the stringers. What should I use for the floor?

Thanks,
Kevin

[MGMS]

You can use any marine grade trated wood as long as you cover it completelly with fiberglass fabric and resin... and I will recomend that once you do this job you replace all the wood... Stringers, Engine Mounts, Transom, Floor, etc. I just replace all in my Ambassador (in fact I sedn it to a marine Shop and pay $4,000.00 since I do not have the time to do such massive labor intense job) and the boat now is like when she was brand new...

Remember to brace the hull into position while installing new stringers and gussets, if not the hull will deform and the boat will not plane properly on the water, any small deformation of the hull will change the hydroplane characteristics of the hull, so be carefull there... Attached are some pictures of my boat.

[sleekcraft26]

Thanks for the input. I saw this boat on ebay before I boght mine. It helped to make the decision. It looks like a nice boat. Where did you get the two front seats for it? I like the cockpit layout, and am thinking of something similiar. I have complete artistic license at this pint at there is nothing in the hull but the engine stringers.

Thanks again for the input.

[Karsten]

I would use foam formers for the stringers, fibreglass and epoxy resin. Marine grade foam doesn't soak up water (probably the reason why the original wooden stringers had to be cut out). Since you have to work inside the hull I wouldn't use polyester. You would have to wear some sort of breathing protection because of the fumes. Epoxy doesn't have those problems.
The easiest ist to make the new stringer geometry roughly the same as the original geometry. Problem is only that you don't know the layup and this is very important. Ideally the vertical parts of the the stringers should be laminated with fibres running in the plus/minus 45 degree direction whereas on the top you want the fibres running for - aft. If you use this lay up and make all the parts of the stringer the same thickness as the original you should be on the conservative side since the original design was probably not as good as this.

[ralph murphy]

I have the same stringer problem on a 19 ft Chaparral. The deck is being cut out and being cut out because of rot and I found the strings are not any better. I am going to replace the bad sections and the foam while I have the deck up. Weight is a big issue so I have decided to stay away from an epoxy filler. what type of wood is the best replacement or better yet what type was used during the original manufacture? Its a 1995 198 C xl cuddy cabin hull. The bow seams to be be heavier than it should so I will most likely remove the and replace the foam in the bow as well. Any ideas?

[yokebutt]

26,

Have a look at the thread called glass selection for repair, or something like that.

Yoke.

[kjoiner]

Hello,

I may start a new thread but I'll try here first.

I was given a 1980 Ebbtide Dynatrak 176 fish and ski boat recently. I've pulled up the floor as far forward as I can (right at the dash area) and found that I have a good bit of stringer repair ahead of me. The boat had a hatch in the center for ski storage which held water and rotted out the two stringers on either side- they basically crumbled. Also, a stringer on the passener side is fairly rotten an needs work. The floor is OK at the dash. The only other area I can't get to is in the bow storage area.

Here's my question(s):

The design of the boat prevents me from being able to fully access the stringers from the front to back unless I want to separate the top half from the bottom half. I've been told that's not a good idea and given that the boat is 25 years old and the hull is only worth about $1300-1400 it's not economical either. The spaces between the center stringers and the outer stringers are filled with foam - it appears to be dry. Can I use pressure treated 2 x 8s for the new stringers and fit them in as well as space will allow and glass over them. The center stringers stop where the back seats and livewell are located. I can't really bond them to the hull from front to back again because of the top of the hull and there's nothing to sister them against.

There are also two small stringers underneath the fuel tank platform (plywood sheet covered in gelcoat). I'm pretty sure they're rotted as well but the fiberglass is intact that covers them. They're hard to get at. Does the wood perform any structural function or does the tube formed by the fiberglass covering really provide the structure? This is located in the bilge area where the boat will be running when it's up on a plane.

What is the structural function of the stringers besides holding up the floor. The fiberglass seems pretty strong, but it gets pounded when running at speed. I'm trying to lean as much as possible so I can reach a balance between economy/less work and not taking a shortcut that will come back to haunt me later.

Would Git Rot work on the passenger side stringer or is it just a gimmick? I've removed the top edge of the glass that covered the stringer to see what shape the wood was in. Can I glass back over that section and restore the strength? I see some posts where foam is used as a form instead of wood and the glass seems to be the important structure.

I want to put some work into the boat but not beyond its value. It has a 150 Evenrude motor that has very few hours and looks brand new under the cover.

Any help/advice would be greatly appreciated. If needed, I could supply some digital pictures.

Thanks,

Kyle

[dr.j]

Picures would help a lot, closeups of the affected areas especially. Unfortunately,shortcuts do not translate into safe boating. Include some photos of the hull to deck joint if possible. Removal only seems more difficult than it really is. If you regard your labour as essentially free, or an investment in your leisure time (as I do...) then your project will not be as daunting as you think it is.

[kjoiner]

Dr J.

Here are some pictures of the boat. The stringers in the middle (where the ski storage compartment was located) are gone - they were mush. The stringer on the passenger side is pretty much gone too and it runs from the transom up to the bow. In the bilge area, that stringer has a shelf on it for the trolling motor battery and that area is covered in what I think is gel coat.
One picture shows the small stringer (about 2 x 2) that is covered in glass. It passes under the gas tank shelf. The wood is rotted out there as well.

As far as the hull attachment, I haven't looked under the rub rail yet, but I think that in addition to any mechanical fasteners, they also applied fiberglass across the joint on the inside. I'll look in more detail tomorrow and let you know.

I agree with you comment about shortcuts. I like to do a good job and don't want to find a mistake either in rotted parts in the future or some failure at 45-50 mph.

I'm starting to think that the boat had a lot of water in it that did not get out.

Take a look at the pictures and let me know what you think.

Thanks,

Kyle

[dr.j]

Thanks for the pics Kyle, I will try to make time to reply to your post on the weekend. Let us know what the construction of your hull to deck joint is. Any more information, including photos, helps. Regards, Jay

[kjoiner]

Jay,

I'll try to get some more pictures and put some labels and pointers on them as well to show where I have concerns. Looking at the 1st picture (top left) you can see the open space in the middle where the storage compartment was located. Those were the two stringers running from the livewell to the bow in that area along with the small spacer right at the keel. Also, about about 6-8" to the left, there is the other stringer that runs from the stern to the front. It's pretty much rotted out except for the knots.

I'll try to get a better picture of the hull to deck joint. At the back, I can see where the top overlaps the hull. As I mentioned before, I think they applied glass to the inside of the joint which might make separation more difficult.

Kyle