Not another Mustang restoration thread.

Alan: Thanks!   May be getting ready for a consultation visit. Still some work to do, but getting to the point where we get together for your expert opinion and direction and of course to drink some beer.

My project just blew up in my face this afternoon. Earier I asked about stringers being glassed to the hull. I got my answer. While starting a little grinding I noticed the starboard stringer was a bit loose. I lifted it out of it's channel without resistance. I can't imagine it had any structural integrity the way it was. It was pretty much just floating in a fiberglass enclosure. Now I just don't know what to do. I think I know my options but this is a real setback. It may make the difference in whether it's in the water this year or not..

John,
Look at it this way, now's your chance to get full coverage on the CPES! After the CPES set them back in the hull in thickened epoxy.

Be aware that you shouldn't lag into coosa directly... I would give consideration to an engine cradle. That will drive some stringer/floor configuration changes (to access the motor mount through bolts at a minimum).

John, I believe you are on track. and nice work by the way!

TRBenj wrote: I can think of a few ways that threaded sleeves and saddles might not be preferable. How does the floor mount to it? Aluminum angle mounted to the outside of the stringer (instead of the inside) would probably be the stealthiest way to add cradle-like support. Then you can scallop the stringers under the mounts and gain access to the nuts/underside from the bilge side.

Good point, Tim. If I through bolt U brackets and epoxy the floor down there is no future access to the outboard bolt heads or nuts depending on orientation. If I drill and thread the outboard side of the angle and through bolt into it that way it could be tightened if that was ever necessary. I could make your design with hand tools, no fabricator required. The simplicity of your design is beautiful. Thanks.

3/4" would be overkill for floor thickness but no harm if you're adjusting floor height accordingly. The glass between layers when laminating adds strength and is about as easy as any other (effective) method of joining them.

The later, larger boats had thinner hulls and relied on the foam sandwich and floor glass for structural support... so more members required when going back foamless. Plus, the v-hulls required ribs/bulkheads. The smaller, earlier boats were offered foamless and don't need all that extra support- so you're right that your build would be much less involved.

8122pbrainard wrote: john b wrote: I see Tim used a layer of cloth between the plys. Is this necessary? John, Yes, it's needed. It's to overcome the lack of strength lost at the 2 butt joints of the Coosa in each of the stringer laminations..

Would a scarf joint be worth the minimal extra effort it would take, or am I overthinking this?

High density foam mixed with glass fibers and some layers of fiberglass (looks like woven roving?) mixed in. Check out the specs, it's strength compares favorably to ply. Much more than just a strengthless core material.

You do lose significant strength at the joints... adding extra glass in this region will compensate. Probably easier than scarfing, though not a bad thought. One of the reasons we went 3 (1/2") layers instead of 2 (3/4"). Still preserves 2/3 strength even at the joints. I think your plan is still fine, though.

Thanks much. I'm going to take some more measurements and try laying out the patterns to scale. 1/2" 3 ply may be the way to go. Coosa makes 12' sheets but I don't think Total Plastics stocks it. It may be special order and therefore expensive. Without all the help from everyone here I would have made far more misakes. I ned to try to get the engine in for paint this week so I should have some time to work on the stringer plan.

81 degrees today. It's nice to work out in the driveway. Much to do.

8122pbrainard wrote: John, Have you considered just using the old wood stringers? The hull sure looks great!

Thanks Pete, it shines up pretty well, but there are a lot of imperfections. . I have given some thought to just treating the existing wood and putting it back together. Three reasons I don't want to.
I don't want to expose myself to that much CPES.
The cost of enough CPES to do this project could cost as much as swapping to Coosa.
It is my opinion that materials with quite different properties don't play well together. I have come to believe that encapsulating wood stringers in fiberglass is the structural equivalent of fiberglassing the bottom of a wood boat.

Back from vacation and ready to do some work.
I appreciate all the advice I have gotten from the experts here, but I am planning to vary from the advice a bit. I hope to pick up the Coosa this week and in an attempt to keep waste to a minimum, I am planning to go with the 3/4 and laminate two pieces for the stringers. I appreciate that laminating three pieces of 1/2 may be slightly more desirable, but it would require me to buy more product to do both the stringers and the floor. The secondary stringers, originally being 3/4, would require me to laminate two pieces and would come in at 1". I am also concerned that a 1/2 floor would not have the desired rigidity. and I dont want to laminate the entire floor. As it is it will need to be laminated at the pylon and seat mounts. I think three plies would be more than adequate there (2-1/4").
The concern about he strength at the joint is unwarranted IMHO because compared to the strength of the wood stringer, which had been drilled for the battery cables and battery tray drain (2X for good luck I guess) It should be much stronger. I believe in my vase, and many others, the stringers are doing nothing more than holding the engine in, and sometimes not performing that task very well. My stringers were completely disbonded from the fiberglass and were just "floating" in a fiberglass capsule providing no rigidity. It is possible that the hull flex from disbonding and rotten stringers has caused some of the gel cracking that seems so common with the older Correct Craft boats. I do not intend to drill the stringers for the battery cables or the tray drain. With a foamless boat and passages to drain the area outboard of the stringers into the bilge via small passages between the hull and the stringers it is unnecessary. If anyone an explain to me how the stringers were providing ANY strength with this disbonding, please let me know. The original stringers in this boat are in much better condition than what I have commonly seen in these threads but I dont think it really mattered much.

turningpoint84 wrote: John, Can you talk more about the dash panel and how you milled it down? i still have mine and it needs the same treatment!!! Thanks, Peter

Hi Peter. I just layed it on the radial arm saw and indexed the cut to the depth that I wanted the panel to be. I made multiple passes with my finest crosscut blade taking out a blade's width on each pass. Not fancy but it worked well. I have a radial arm saw up in MW too. I'm here now and most of the summer. I'm busy building a new garage right now. If you're coming up stop by and I'll do it. I hope you can make it up.

Just about ready to get this party started.