C19 in Richmond, VA

[OneWayTraffic]

Build looks good. I must admit I thought the same as TomW when I saw those chases running through the stringers like that. Best to have cutouts in the middle 1/3 of the stringer. The sole on top will help, but I'd run it by the designer for an opinion.

You could sister on a support next to the stringer, or place a shelf or something above the sole there.

[cape man]

Make sure to fill any gap between the pvc and the stringers with thickened epoxy and you should be fine. Once hardened, the pvc will become part of the structure. The force on the top will be widely distributed with the sole and the wide cleats sitting on top, and it would take one hell of a force to compress the pipe. The other comments are correct in it would be better to go through the stringers more centrally, but you should be good as installed.

[OneWayTraffic]

Make sure to fill any gap between the pvc and the stringers with thickened epoxy and you should be fine. Once hardened, the pvc will become part of the structure. The force on the top will be widely distributed with the sole and the wide cleats sitting on top, and it would take one hell of a force to compress the pipe. The other comments are correct in it would be better to go through the stringers more centrally, but you should be good as installed.

Other concern would be whether the section moment of inertia of the stringer is too small with the cutout. Especially with several cutouts close together you effectively have a dogleg, not good in stringers. I suspect that it would be ok, if there is at least 75mm (3") over the bottom, but there will never be a better time than the present to take a couple of good photos and ask the designer.

[VT_Jeff]

Dan,

I'm quite certain you can drill the same sized hole, the same distance from the flange, every few inches along the top and bottom of that stringer without any structural issues.

Truss me on this.

Drill on/build on!

Jeff

[OneWayTraffic]

Dan,

I'm quite certain you can drill the same sized hole, the same distance from the flange, every few inches along the top and bottom of that stringer without any structural issues.

Truss me on this.

Drill on/build on!

Jeff

I'll bite. How are you sure? It's almost impossible to accurately calculate the forces on a boat at sea, in waves. And if fatigue is an issue, it could take years to show. If it were mine, I'd like to not be worrying about it. Unless there's other C19s with holes there used in similar conditions for years, or it's already been answered in another post. What does it cost to ask the designer?

[VT_Jeff]

Dan,

I'm quite certain you can drill the same sized hole, the same distance from the flange, every few inches along the top and bottom of that stringer without any structural issues.

Truss me on this.

Drill on/build on!

Jeff

I'll bite. How are you sure? It's almost impossible to accurately calculate the forces on a boat at sea, in waves. And if fatigue is an issue, it could take years to show. If it were mine, I'd like to not be worrying about it. Unless there's other C19s with holes there used in similar conditions for years, or it's already been answered in another post. What does it cost to ask the designer?

I have no idea, OneWay, just providing an alternative guess. Sort of the "One Dollar" answer, if you get that reference.

[OneWayTraffic]

I'm afraid I didn't. We get a lot of US culture here, but some of it goes over our heads. Two countries divided by a common language.

Anyway I think that the stringer would be fine, but I'd sure like to know for sure. I decided not to have any chase tubes in my boat for reasons like this. Would rather go under a gunwale.

[VT_Jeff]

I'm afraid I didn't. We get a lot of US culture here, but some of it goes over our heads. Two countries divided by a common language.

I'm going to do the group a solid and not explain it.

I will say that I did some quick research that showed only an 1/8" of flange is required when holing an I-member, and I know that trusses are used ubiquitously, and I know that drilling large holes in stringers/frames is a common way to reduce weight, so those anecdotes went into my otherwise totally hazardous guess. Dan's not going to make any decisions based on my ramblings in any case, he knows far better than that.

[TomTom]

Dan glad to see such great progress on your build.

I was thinking about your white chase tubes there and maybe if you are worried you could wrap the pipe with a few layers of Fiberglass tape to stiffen where they pass the stringers just to stiffen up that portion. It would also be a better bond to the wood.

[OneWayTraffic]

Now I think about it, I'd probably just make sure that the sole is really really secure on the cleats. I'd put biax on the top of the sole anyway, and that would help. Other thing I'd do is ensure that the seams in the sole are separated from the pvc tubes.