I'm a Boat Builder! G-L Ski Tow under construction!

[chugalug]

Looks good!now you will have a spot to glue and fasten ply to instead of a void.it won't be seen but you'll know its there.I'm building the Bo-jest(3 years along now)my stem was straight up and down.real fun to bend ply.

[Mark-NJ]

Things are moving along at a very nice pace! Fairing is done and the hull frame is just about ready for skinning with plywood.

My last task before skinning is to drill holes for the transom drains.

I bought a pair of transom bailer tube / plugs, and I'm putting some thought into the holes that need to be drilled for the tube. At first glance, this is simple. Further thought has me scratching my head.

Pardon my simple sketch...I hope this makes sense.

Because of the 12 degree tilt of the transom, drilling through the transom is not straightforward.

- If I drill perpendicularly to the transom (fig A), the scupper's rolled edge will sit pretty to the transom, but the tube won't be at the bottom of the hull inside the boat, so it won't fully drain. The lip of the tube will be about 3/8" proud above the floor, which seems pretty significant.
- If I drill parallel to the keel (fig B), the clean, flared end of the tube won't sit flush to either side of the transom. Functional, sure....but amateurish in appearance.
- If I drill for perfect draining (fig C), the tube will extend out the bottom of the hull....clearly no good.

Any ideas? Or maybe these are not intended for angled transoms....




The only option I can come up with is "fig B", and cut off the tubes flush with the transom, so that the tube is in line with the hull for best draining, but the flared ends get sacrificed. I guess once the tubes are epoxied in place, it really won't matter that there's no "finished flair". Still, with that, the plug won't fully insert...

Thoughts? Comments?

[gdcarpenter]

I came up with the same 3 install design options as you have. I opted to NOT install drain tubes. I have 2 bilge pumps for redundancy that dump into my motor/splash well, and from there dump into 2 drain holes at the bottom of the motor/splash well.

[Mark-NJ]

Hmmmm......."Option D": don't install them at all.

I hadn't thought of that.

Glad to know that I'm not alone in my observations, though! Thanks!

[rbrandenstein]

If you want drains, sketch B is the right way, with maybe a little tilt to it. While the sketch is exaggerated, the actual transom angle is not that great and the flares on the tubes sit flush with a little sanding.

[jenko]

I would have thought option c would work if you take into account the thickness of the hull.
if hull is 1/2 inch thick and transom 2 inches thick it would still work if transom angle is 11 deg or less

[Mark-NJ]

If I follow "fig B" (which I agree is the best architecture for draining), the lip on the tube will be sticking out quite a bit....

offset = dia * TAN12 = .21256"

That's quite a lot to try to compensate for.....

[gdcarpenter]

I have seen some one ZIP that ran the drain tube dead horizontal through the angled transom, then just sanded off the ends. In my 30 plus years with boats it is most often hull penetrations that eventually leak and cause rot.

I would say option "A" is the least objectionable since it leaves the drain plug most reasonably accessible and provides a good seal on both ends. Have to 'swab' the rest!

[Mark-NJ]

In my 30 plus years with boats it is most often hull penetrations that eventually leak and cause rot.

And there's that, too.....

At this point, I'm heavily leaning towards "D".......just omit them altogether.

[Andy Garrett]

Mine is more like A. Maybe a bit of A and C combined.
B just looks problematic to me because the plug (most designs) will not fit flush--could snag and get pulled out in shallow waters.

[Andy Garrett]

My Zip gets a lot of slash and sometimes a quart or two of water in the bilge.
No holes would not work on my boat.

I have a drain on each side of my keel.

[Mark-NJ]

I'm going to have to sleep on this one for a couple of nights. I'll circle back in a few days....

Meanwhile, I was having another thought. As I stated, I'm just about ready to skin the hull, so I've been giving that a lot of thought, too.

While I'm loving the Poxy-Grip from Glen-L, I've been wondering if it might be easier to apply the plywood skin with 5200. It's flexible, has good working time, can be easily laid on in whatever thickness is needed in any area, and it's strong!

Has anyone done this? Are there any reasons not to do this?

I'm open to any & all suggestions / warnings / stories, etc.

[gdcarpenter]

"5200" 'bottoms' are the current rave for restoring old Woodies. The most common application seems to be a layer of marine ply bottom installed first, then planked over using "5200". It is, by all accounts, PERMANENT! - which is appropriate in your intended use, and I suspect would work well - though I have not heard of a GlenL builder using it yet for the hull.

If you park your finished boat outside hull drain plugs are likely quite useful and convenient, self draining whenever it rains. Mines garage stored so that's not an issue, and she stays dry running - the bulge pumps clear out the bilge when she's afloat for long periods of time and is left out in the weather.

Theoretically if you take on water while at sea you could pull the drain plugs to drain the boat while running: if you can get to the plug! Personally my most vivid experience with drain plugs is launching the boat without reinstalling the plugs!

[psychobilly]

A lot of the old Desko boat's lives are being prolonged by 5200 over the planks, screwing plywood, and then glassing. My skiff that's going on 20 years old now was built using plywood sides and bottom, put together with cypress chines and 5200. For 18 years there was only glass on the seams. I totally glassed the outside with Poxy Shield a few years ago. 5200 is tough as nails but very expensive.

[vupilot]

I too went without any at all. I figured if I wanted them later it would be easy to install after the fact. In 6 years there has been only one time I wished I had them. When I trailered in the rain for 3 hours straight. I pulled over about halfway into the drive and ran the bildge pumps and drained a couple gallons.

Unless it rains while on a weekend getaway my boat gets zero water in it. Contrast that to the Utility I bought used from its builder and had the drains in it. They leaked and I had to repair them to prevent damage. After that I decided that sponging out the last few drops the pumps cant reach after a rain wasn't too bad. Even with drains youre not going to get every drop out without a sponge but you can rinse the boat out with a hose or trailer with them out and not worry about rain. Its more a question of how you will use your boat and if its inboard or outboard. Inboard I would always have them, outboard and the boat stored under roof, I wouldn't.

So in my case of a outboard trailer boat that stays in the garage unless being used drains were not worth the potential long term issues I have seen in the other boat I bought used.