stringer, crossmember, transom configuration

Hello Everyone,
Yet another newbie in distress. I have a 1973 Volora 176 by Larson Possibly a Glasspar V-175 version just a guess because Larson bought Glasspar around this time. The boat was an I/O but was a Outboard when I got it.
I have a 90hp Mercury thunderbolt 1973 , and a 10 hp Johnson kicker that i hope to power it with.
I noticed patched cracks along the ridge lines near the stern so decided to investigate under the floor it sounded dead in that area no backing, so started taking the floor up. Here we go, it had been done improperly before there was a gunnel 12" wide with 1/4 walls tapped in to cross members and the bottom and it was just slopped in and then buoyancy foam to support the rest of the hull. I am also not so sure of the transom being constructed and reinforced properly.
So enough history for now. Currently i have the hull completely stripped and need help with the arrangement of the internal structure i.e. stringers and cross spans and i really do not have the original placements for orientation ( Even have tried calling Larson in Minn. and the guy at the tech dept laughed said the probably sketched it on a piece of paper and threw it in the trash after they made the proto-type.) so i am in deep dew. because I have done a lot of research and tried to do my part and learn as much as I can i come to you guys and thank the people on this forum in advance for any guidance.
What i have bought so far is 3 gallons of vinyl ester 18yrds. of cloth / mat and 4x8 sheet of 3/4 marine ply.
My first step was going to be to lay down a mat,cloth,mat lamination over the whole interior of the hull from where the deck lays downward then encapsulate the 3/4 ply for two stringers @ 12" apart down the center and evenly space two more 1/2 distance to deck joint (chine?) and some sort of support at deck joint. Not really sure whether these should land in relation to the ridges I would think rite at them, and I know about avoiding hard spots , but don't know what filler to use for this. Across the stringers I was going to put 3/4 x 6" cross members every 24" to 30" the length encapsulation and fill the voids with foam.
Mike- Cleveland,Ohio



Hopefully the attached pictures will help I can always take more

Re: stringer, crossmember, transom configuration

I can't help much with the replacement of unknown (length, location, quantity, or height) stringers, sorry beyond the scope of my input. However, since this WAS an I/O and was converted to OB at some point & you want to keep it that way, I'll start there.

From the demo pix, and your plan, it doesn't sound like you have much re-work or demo planned for the transom. I'd suggest that you step back & make a plan that includes reworking the transom. It doesn't look like the plywood transom, the actual support for the OB's, is full width across the fiberglass skin of the stern. And certainly doesn't appear to be fully glassed in place. There looks to be a framework, w/ aluminum brackets (thru bolted? hard to tell in pix #5), resting on the remainder of 1 of the decks that have been in this hull.

From pix #1, it seems like the transom was cut down from full gunwale height to accommodate the OB's. You might post a straight on shot of the stern. Regardless, I think there should probably be some transom re-work pending in your future. And construction of some sort of splashwell if there isn't 1 currently. Hard to tell what that area might currently look like in pix #4. A pix of the stern from above would also be helpful.

The stringers all terminate at the transom, so it would make sense to me to start w/ the transom work....

Re: stringer, crossmember, transom configuration

This ^^^^ is ALL very sound advice. Anytime an I/O is converted to and OB the transom is a critical aspect of the modification refit. You should pay very close attention to this and make absolutely certain that this has been done correctly an is sound especially since you will be hanging those motors off of it. Everything else depends on it.

Re: stringer, crossmember, transom configuration

Thanks for the input,
I did not expect to be where i am and once I got into the floor, it blew my mind i am new to all this.
Anyway no excuses I am here and not a quitter if I floater on my back. I am trying too do my apart and get as much info as possible and I am not in the maritime circle except here and i know you guys know what your talking about but Ive been trying to find someone to come and take a look that will come with time i have faith I one tanashis Irishman and my aniecters fished the rivers in Ireland.
The thing is I am facing winter in Cleveland in the drive without no floor or support for the hull thought I could brace transom sub-deck and connect above deck as weather permitted even if I have to re due some in spring.
I was figuring on 4/4's attached @ 2' down outside of gunnel stringers not sure what made of, I am very grateful to any input and will act accordingly.

Thank You