TOPIC: Stringers, woah woah Stringers (Sung to Feelings)

Ok, started process of removing floor and have a few questions:

1. How are stringers attached to Hull on Dorsett? Looks like maybe a fiberglass "L" on either side. Is that correct?

2. Replacement Floor - Floor is 1/2" plywood with an additional 1/2" layer in center. Does that mean someone previously just covered over with a layer or was that done at manufacturer? Any downside to just doing the whole thing with 3/4" marine?
3. Assume I can go with a few pieces rather than one complete piece of plywood?

IMHO it's much better to fully enclose the stringers in fiberglass, for strength and protection. My material of choice there is 1708 biaxial mat.

It does sound like someone added a "repair" job to your floor, I seriously doubt they doubled it up at the factory. 3/4" is going to be awfully heavy, 1/2" or 5/8" should serve you well as long as you glass both sides with CSM.

Multiple pieces are okay, just try to use as few pieces as possible and put the joints over the stringers or ribs (cross braces) for support. That's (the joints) another good spot to use 1708 biax (tape).

Everyone has their own thoughts on the best way to approach this, just the way I learned from the gang - others may have alternative thoughts on the subject.

If the original floor was 1/2" stick with it.
You will create other issues by going thicker.
You really want to leave a tiny bit of fiberglass on the edges, so you can tell where you need to be. Floor replacement isn't bad once you get going. Just study the floor to transom to see if they are married in any way.
How is the condition of the wood stringers.

I did a Starcraft Tri Hull. I no longer have any wood in my stringers. I removed all the wood and doubled up on the glass.

Mark,

Thank you very much. Appreciate the tutorial!

I tear out everything right down to the hull bottom and replace with stringers and blocking made of mahogany. I secure them to the bottom with copious 3M 5200 so that "squooze" comes out everywhere. I generally weight the stringers down with old marine batteries and anything else I can find that's heavy and then leave it alone for a week. After that, I liberally coat all the wood with CPES and fill the bottom with marine foam flotation right up to the tops of the framework. Cover all with 1/2" okoume marine plywood (Talk to Al Jernigan in NC at World Panel Products)and fill all seams, edges and holes with 5200. Finally, the whole "floor" is covered with fiberglass matting and resin to a point about 4" up the sides...a totally encapsulated bottom that will outlast the restorer...by at least a decade.

The REAL trick is to get the new decking even at both sides and dead level without distortion, meaning that you have to work from some kind of homemade scaffolding. If you stand inside the boat and try to fit stringers...well, it's impossible.

Hi Jan,
I understand the stringers and floor have to be level.
My questions are:
Before ripping the floor and stringers out, do you level the boat, in its boat stands or make shift supports, to the painted waterline on the outside of the hull, or the old floor, before you rip it out ?
Then can I assume that with all the ripping, tearing, grinding, and cleaning, that the boat gets out of level from climbing in and out ? and then re-level it before installing new stringers ?
Or are you doing all of the demolition and re-installation from the overhead scaffolding ?

If the boat is crooked fore or aft, port or starboard, and you put in level stringers and floor, as soon as you put the boat in water. the floor is crooked ?

BTW…. Any updates on the Trans-Am, Dee White, or Shepherd ?

Fantastic write up. Very much appreciated!

Chuck:

It's all very tricky. We chock the boat in three places: at both rear corners and under the keel as far forward as possible. Then we strip the hull bare. It's always obvious where the "floor" meets the sides but in some cases, the factory wasn't too picky about level. We are. We make a couple straight edge boards (on edge) to fit inside the boat that rest where the bottom meets sides...at the chines...as far fore and aft as possible. Using these planks for support, we use another long and dead-straight plank laid on them fore and aft, positioned precisely where the new stringers will be placed. We take our measurements (about every 6") from that board while on the "bridge" we've made to work from, subtracting the thickness of the supports. We use these measurements to make plywood patterns that can be "tweaked" after successive trial fits. When we're satisfied with the fit, we trace the patterns onto 1-1/2" thick mahogany planks. The stringers always need to be beveled to fit the bottom and to insure a snug fit...several times, which is why we always measure the depth of the new stringers from the "deep" side. It takes time. Then we connect the stringers with cross beams to keep everything plumb, level and square. The resulting "box" is then bedded to the bottom with 3M 5200, held down with weights. All this is done from the "bridge." After that, we have our wives rub our lower backs with Ben-Gay.

As for the other projects, it's been slow going. We've had a couple clients put their restorations on "hold" for various reasons and my Shepherd (to be converted to a racer) hasn't been touched, aside from building the V12 engine...which is becoming damned expensive and time-consuming! I'll post photos when the engine is done...sometime in November? Good guess. (I'll be in Japan most of September.) The Dee Wite will be brought into the shop and flipped on Monday in order to do the bottom. When that's done, we'll go to town on the topsides. The Chrysler straight 8 is already finished.

Sayonara!

Here's how I do stringers. I laminate 2 pieces of 3/4" Aruaco Plywood to get the required length using Titebond III wood glue. I then saturate them with Polyester resin paying close attention to the edges and if there are any voids I fill them with thickened resin. (Resin thickened to the consistency of creamy peanut butter using Cabosil) When the resin tacks up I Install the stringers and user 1/4" spacers to keep em off the hull. I then mix up a bunch of the thickened resin and put it in a quart ziplock bag and cut off a corner. I then use the bag like a pastry bag and squeeze the mix out along the edge of the stringer to form a fillet. I use a teflon spoon to form a coved fillet and push the mix under the 1/4" gap. This coved fillet makes it easy to apply the glass tabbings. Once the fillets are cured I lay my first tabbing of 1708 1/2 way up the side of the stringer and about 4" out onto the bottom of the hull on both sides of the stringer. When it tacks up I lay my final tabbing all the way to the top of the stringer and 4 inches past the previous tabbing out onto the hull. I then Cap the top of the stringer with 1 layer of 1.5 oz CSM that I tear and make FUZZY to make it easy to lay over the top. That's How I do it, and have not had any issues.

Keep up the good work it'll be worth it!