Touring T-V (SS) Electric

Builder show and discuss their progress.
Kayak Jack
Design Reviewer
Posts: 1186
Joined: Sun Jun 20, 2004 8:03 pm
Type of boat I like: <-- Please read instructions to the left and delete this text. Then, tell us what type boat you like! :-)
Location: South-central Michigan

Post by Kayak Jack »

tw541 wrote:... I will be carrying about 150 lbs. of batteries and the motor weighs about 18 lbs. I think maybe I need to look into adding foam.
Or an ejection system for all the lead and copper.

If you round that off to 170 pounds, that makes about 2.84 cubic feet of water to be displaced. Considering that whatever you put in will also weigh something, about 3 cubic feet of floatation.

And, it should be located where the weight is. Don't want weight in one end, and flotation in the other. So, maybe a box to surround the battery bank? Box is made of Styrofoam with thin plywood to protect it? Heavier wood on bottom? Kind of a PFD for batteries.

Just running off at the mouth here, some thought-fodder to kick around.
Kayak Jack
Doing what you like is FREEDOM
Liking what you do is HAPPINESS
I spent most of my money on whiskey and women - and I'm afraid I just wasted the rest.
tw541
Posts: 73
Joined: Thu Feb 28, 2008 8:19 pm
Type of boat I like: All boats
Location: Mountain Home, Arkansas

Post by tw541 »

I found a problem on boat #1 today. The hull is not straight on the center line. In the center on the bottom piece joint, it is bowed 5/16". This is in about 30 inches. It is an even bow, equal on each side of the bottom panel splice.

Image

Image

I checked hull #2, and it has about 3/16" bow in the same place. It's a little funny that I spent 3 days assembling the panels for boat 1 and part of 1 day doing the same work on boat 2! Boat #2 is the straighter boat. I tried blocking up under each boat to try to take the bow out. Boat 2 with the 3/16" straightened out perfectly. I think the 2 layers of fiberglass on the bottom will hold it in place. Boat 1 was a different story. I could lift the boat off the sawhorses and still not eliminate the bow, so I decided to take more drastic action. I cut a sawblade width out between the bottom panels for about 16 inches each side of the panel splice, where the bow was centered. I then blocked up under the center of the bowed panels, and it lined up fine. After gluing it back, I think this cured the problem on this boat.

Image

Image

I started to do it the same as the other boat, but I was using my drill as a weight to hold the panels aligned on boat 1. Not much of an excuse not to fix it right. I am still debating doing the same as I did to boat 1. I have already decided to stop rushing and let these boats get finished when they are finished. I would appreciate any suggestions or opinions on whether the fiberglass will hold the hull straight on the boat I did not cut and reglue, it is only bowed 3/16", and is completely straight with the blocks under it. It is bowed in the same place as the boat in these pictures. In reality, I don't think that this bow would make any difference. Even the worse boat would not have been a real problem, but I want them as good as I can make them.

Jack, I really like your idea of an ejection system for the batteries. Maybe something Air Force surplus would work.
Terry
jem
Site Admin
Posts: 4915
Joined: Fri Jun 18, 2004 8:14 pm
Type of boat I like: Wooden
Location: Greensboro, NC
Contact:

Post by jem »

This is where the spacer technique is useful. Can you push a thin shim in the gap and sort of use it to "pull" it into place by forcing the wood to bow up because it's squeezing the shim?
-Matt. Designer.
tw541
Posts: 73
Joined: Thu Feb 28, 2008 8:19 pm
Type of boat I like: All boats
Location: Mountain Home, Arkansas

Post by tw541 »

When I cut between the panels and blocked up under them, they came into alignment. I then reglued where I cut the joint out. I think this boat will be straight when the glue sets. I am a little concerned about the boat I didn't fix. It is straight with the blocks under it, I hope it remains that way after being fiberglassed. I still may cut and reglue it tomorrow like I did this boat. I spent a lot of time looking at and aligning the other joints on both boats. I ignored this bottom joint. The rest of the joints on both boats are very straight and look good. I really think I will cut and reglue the bottom seam on the other boat tomorrow. I don't think it would be a problem, but I would always know it was there. I also think the spacer technique is probably best. I got in a hurry on these boats, and did not spend enough time making the technique work. I will try it again on the next boat.
Terry
tx river rat
Posts: 989
Joined: Wed Feb 21, 2007 10:48 pm
Type of boat I like: <-- Please read instructions to the left and delete this text. Then, tell us what type boat you like! :-)
Location: Tx

Post by tx river rat »

Terry
On my T-V I had one spot that I had a wide crack in on the bottom seam
that if i had pulled it together would have made a bow in the bottom, I just figured I got of off the line a little .
Ron
tw541
Posts: 73
Joined: Thu Feb 28, 2008 8:19 pm
Type of boat I like: All boats
Location: Mountain Home, Arkansas

Post by tw541 »

Ron, I think that is exactly what happened with these boats. I had a small gap between the bottom panels, and I think I overtightened the steel wire I used for assembly. This pulled the panels flat where it should have had a V bottom. I went ahead and cut and reglued the second boat as well. Simple and easy fix. I don't think this slight bow in the hull would have been a problem. I would have been the only one who would have known it was there, but I would have known and it would have bothered me. I've decided to slow down and enjoy building these boats for the summer. It is too hot to use them here until October or November anyway. I was rushing to try and get the epoxy work done before it got to our usual summer temperature here. However, I now have my garage air conditioned and can work in comfort. I never realized what a luxury having an air conditioned work area in the desert really is.

After cutting and regluing the bottom seam, I got the sealer coat of epoxy on the bottom and sides. I was a little surprised how much epoxy the plywood soaked up. I rolled on 3 fairly heavy coats, and the wood just kept soaking it up. I would let it set for a while and then squeegeed it off after each coat, but I did not remove a tablespoon of epoxy from each boat! I used several inches of epoxy and hardener from the gallon jugs.

Image

Image

Image

This okoume plywood is some good looking material, even if a little thirsty for epoxy.
Terry
jem
Site Admin
Posts: 4915
Joined: Fri Jun 18, 2004 8:14 pm
Type of boat I like: Wooden
Location: Greensboro, NC
Contact:

Post by jem »

that's unusual to hear okoume was resin thirsty.
-Matt. Designer.
tw541
Posts: 73
Joined: Thu Feb 28, 2008 8:19 pm
Type of boat I like: All boats
Location: Mountain Home, Arkansas

Post by tw541 »

It might have something to do with the temperature. It was 115 to 120 in the garage when I got home. I turned on both air conditioners and dropped the temp 25 or 30 degrees in about an hour. The wood soaked it up like a sponge. I rolled it on and could see it disappearing into the surface. It looks wet and shiny in the pictures, but 5 minutes later it was soaked in and there was nothing to sqeegee off. I knew that falling temperature in the room like this should draw it into the wood, but this was pretty impressive. I had left the epoxy in the garage so it was hot and pretty thin. I'm not complaining, I want it to be saturated. I gave it all it could soak up, I'm not really trying to see how light weight I can make these boats. I'll do it the same way when I do the inside.
Terry
jem
Site Admin
Posts: 4915
Joined: Fri Jun 18, 2004 8:14 pm
Type of boat I like: Wooden
Location: Greensboro, NC
Contact:

Post by jem »

oh ok that explains it.

Well you got yourself some VERY deep penetration into the wood grain. 8)
-Matt. Designer.
Kayak Jack
Design Reviewer
Posts: 1186
Joined: Sun Jun 20, 2004 8:03 pm
Type of boat I like: <-- Please read instructions to the left and delete this text. Then, tell us what type boat you like! :-)
Location: South-central Michigan

Post by Kayak Jack »

Terry, as a rule of thumb fiberglass will solidify plywood into position. If, however, there is tension or pressure on the wood when fiber glassed, it will tend to return towards its original position when the tension/ pressure is removed. It will not go all the way; glass will restrict its movement somewhat.

You may have to bend the wood past the position of straight, glass it, and let it return to near straight? Then, when you glass the other side you get another shot. Best, though, is to have the wood assume the position you want before glassing.
Kayak Jack
Doing what you like is FREEDOM
Liking what you do is HAPPINESS
I spent most of my money on whiskey and women - and I'm afraid I just wasted the rest.
Post Reply