Modern Materials for Stringer Rehab

Gregory,
You've mentioned vacuum bagging a couple times. Although a great method, I feel it would definitely complicate a stringer job and really isn't needed With careful layup and using a layup roller will do the job very well.

Hollywood wrote: However, many of us have chosen to modify the factory design for many reasons.

OMG   How could you do something that is not "Original"???   I for one could not sleep at night.

Interesting stuff for sure...
First, Gneil, thanks for starting this new thread. I started the "hull modification' thread and have managed to morph it into an engine/boat 'diet' thread. Really, I jacked my own thread...

Anyway, referenced in that thread is a link to a gen2 SN component weight chart. I found it surprising that a full composite stringer/floor system added 60 lbs. to the hull (if I read it right).

So while interesting and worthy of discussion and exploration, not convinced that the materials costs outweigh the benefits. Pretty sure more can be done with new wood replacements to ensure a longer stringer life than was achieved by the factory.

Gneil wrote: With wood in mind, would you consider a baltic birch ply or would you use spruce?

No on ply unless you consider LVL with all the veneers grain running lengthwise. The other issue with Ply is the 8 foot length problem. Scarf joints? You still have the grain direction problem!!

If you consider any wood, a CPES is a must.

Gregory,
I've always used Smiths (rotdoc) CPES and feel it's a great product despite the rather high cost. The other day I found I was running low on my supply of Rotdoc so I decided to order some Total Boat penetrating. since I am hearing good things about Jamestown's Total Boat line. I haven't had the opportunity to use it yet but will report when I do. I will per the instructions mix it with acetone to further reduce it's viscosity.

Gneil wrote: Rodger, Hats off to the Ballast tanks and stringer/floor job you linked me to. Wow!!! Quite the craftsman. Very impressive. I sincerely enjoy the poof of concept the images and description provides. Did you vacuum bag any of your parts or just lay-up and set? I would imagine if you are doing such a complex form vacuum bagging might complicate matters in the wrong way. Brilliant Job!!!

Gregory thanks for the kind words ... I only used a cheepo vacuum pump I had at the time on my battery box ... yes I found it a pain to do that's why I used what I had to hand in the factory clear pallet stretch wrap ... found the 2 ft wide is best as its thicker if you need narrower just cut the roll to size on a saw.
There are many great minds here from all walks of life that gives the site a great knowledge bank to call on .
Don't over think the build and keep your eye on the prize a boat back on the water running documenting everything takes a lot of time .

good morning roger,

Thank you for your encouragement and experience. Part of my thought process and training is to plan and document prior to implementation. Its very hard for me to except a "one off" strategy without documentation, so if not for me maybe this effort will help the next fan. As you cracked the dreaded dust problem, I see the stringer issue as one that still needs some help and opportunity for improvement. As a carpenter you come by this naturally, most do not. Also problem solving is fun, sometimes mad fun!

I truly appreciate the great minds here in this forum and love the enthusiasm in making and then enjoy the fruits of our labor.

The way I see it, if i get a good nights sleep, I'm not overthink it. ...Ha...

Good morning Pete,
LVL's are a good source of material that will provide proper structure as a ready-made material. A couple of questions that come to mind, without knowing the answers are; how does the weight of the material and efficiency of the form effect the overall structure? And might there be a modern form with a traditional material, similar to an air plane wing, that would provide a ready made model for this application?
I understand the hull and the floor as doing this with the stringers connecting the two surfaces.

Maybe just food for thought.

Thank you for the tip of ordering the LVL's with out the coating. I'm guessing this will help with the penetration and adhesion of the CPES. Is this also the thought behind thinning the epoxy with acetone?

I also saw the 1 3/4" thickness issue with LVLs. Thanks for the heads up with this.

Hey All,
As many here may know, "Coosa advertises 40-60% lighter than ply-wood".
I can't wait for my samples to arrive.

Thank you Joe for providing some clarity. Your experience is valued here.

Gneil wrote: I just got off the phone with Sandra at C&S Marine in NJ. She and I had a very productive conversation regarding the design and construction of the new stern seat that i'll have them make for me.

You seem to be weight conscious. I have similar feelings concerning weight. That is why I fabbed up for my stern seat frames, very light aluminum. You may be interested in looking at my thread "MUSTANG 17 REBUILD". I removed a lot of original weight and built many parts with light weight in mind. I have even built a ski pylon out of aluminum tubing that is exact replica of the 30+ pound original. It is for looks only as I would not trust it for pulling. Plans are to weigh the boat in a week or so and see what the final figure is.   Duane

Gneil wrote: Hi Duane,Very impressive!!! How do you plan to keep them in one place? Also, if they are light do you plan to put them in and take them out frequently? Your aluminum frame reminds me of early aircraft framed seats. Seems like it would be extremely light. very cool fab' !!! any designs in the upholstery yet?

Rear seat:       bottom hinges and back hooks
Front seat:      hinges

I like the color scheme as well. What weight carpet did you end up using? Looks like 32 oz?

Hey Roger,

Thank you so much for the encouragement. Very important coming from a seasoned fabricator like yourself.

All I can say at this point is that Ill be using an epoxy resin. (West Sys. type) Of the limited research that I've done, this seems to be the easiest to use and has the best compatibility with many dissimilar materials that I will be using for my rebuilding of the stringers and floor. Other than that, it is early days for me and i can tell from this group that the quality bar is so high, I'm not sure I can see it yet.

Thank you for you gracious and inviting words. Cool guys! I'm feeling comfortable already.
Cheers!

Gregory, email me or PM me your email address and I will send you the AutoCAD .dwg file Roger created if you want. My EM is CQuinn@GFGR.com. I should probably just send it to Keith also so he could put it in the reference section.

MW,
Hey there! Not much to report here I've been hunkered down here with work...sometimes when it rains it pours! All good though I plan to start the demo etc. in about a month. Chomping at the bit. I can't wait to get into it ; ))).

I Have to buy a couple of tools but other than that I'm ready to go. After the demo I will do a precise survey of the hull and map out exactly where the new stringers are going to go. Still leaning toward the Corsa 26 material. "I hate rot"!!! so I'm looking forward to the build and excited to make some little tweeks her and there to utilize that space as best as I can.

Still have not made up my mind in the color scheme. I may just go traditional but thinking of some other options too. Hum... Plenty of time for that stuff. Also thinking of some engine mods. heads, intake manifold, things like that. First things first. (that means stringer and floor demo. I plan to do the wet grind method, complete with a catch basin and filter sys. I have a couple of ideas but thinking about building a temporary heat shrink wrap cover to climate control the elements.

Here's a question.... Have you ever heard of any one demoing the stringers with out removing the engine ? Sounds silly, but if I don't need to I'd rather not.

How everyone had a great winter so far. Spring skiing in right around the corner!
Cheers!
G. Neil.