wavy bottom edge | SouthernPaddler.com

wavy bottom edge

Scooter

Well-Known Member
Anyone else have this problem?

Think my solution will be some temporary chine logs screwed in through the sides until the bottom is attached and cured. Then the logs can be removed and the wave will be gone.

On one hand I'm tempted to go ahead and attach the bottom because this will be below the waterline anyway, and mostly invisible. Except it'll also be on top of my car and visible to me and anyone else who walks by, and I don't like the idea of building something crooked.

Shoulda selected some flatter ply, but there wasn't much to pick from...I got the best two of the five sheets they had in stock.
wavy1.JPG

wavy2.JPG
 

JEM

Well-Known Member
The ply lacks stiffness. That's why it's wavy (no comments about Viagra please :p )

Here's one solution that you could do but would slighty alter the look of your boat a little.

Unstitch the side panels and lay them flat. Cut a 2" strip of plywood that matches the shape of the bottom of your side panels. Glue the 2" strip along the bottom edges on the the exterior. Let cure, the reassemble the hull.

That will give the ply a little extra stiffness but not too much while providing you a more fair curve. When you apply the fiberglass tape to join the bottom to the sides, lay the glass up the sides just enough to cover that strip. That could also be the limit of any graphite you might decide to apply.

Let me know if you need a sketch.

Your chine log would work too. You'd have a bunch of screw holes to fill in but that won't be too bad of a job.
 

stevesteve

Well-Known Member
Sep 5, 2006
111
0
UK
Hi Scooter. I had exactly that problem.

I thought that this was caused by the smaller ribs being attached slightly too close to the centre rib so that it pulls the sides into this slghtly 'waisted' shape. Now having read Matt's post I think that he is right and that it was fine untill I put the rail on and yes, I suspect that the ply flexes so that it flattens the rocker slightly, bulging the lower margin like this. You have rails that look like they are 11/4" x 3/4" which is the same as I used.

I tried to resolve it by drilling small holes (~1mm or say 1/25") then putting a wire attached to blocks through the hull to hold the shape better before fixing the bottom on.

I still have a slightly wavey bottom (Oooh err Matron!) but I am trying not to worry about it.
You cant see it easily here:
pir_filleted.jpg

If anyone comments I'll poke 'em in the eye!
 

hairymick

Well-Known Member
Dec 8, 2005
2,107
2
Queensland, Australia
Hi Scooter,

I had the same problem with the UJ piroge we built in prison.
We overcame it with chine logs. we put them on the sides and then replaced the ribs.

We used 11/2' X 2/8" pine, clamped and glued to the bottom, outside edges of the sides. you will need to take the sides off the boat to do it properly.
 

Kayak Jack

Well-Known Member
Aug 26, 2003
13,976
171
86
Okemos / East Lansing Michigan
I can see the disappointment in getting almost done with a crew on a project. Someone doesn't want the convicts to feel any satisfaction there. The second worst thing in the world is a petty bureaucrat who has power only to stand in the way of others.

The first worst is the nerd's supervisor who sees it - and doesn't stop it.
 

Scooter

Well-Known Member
Used drywall screws to tighten down against some temporary chine logs and was able to get the worst of the waves out. Got a pretty uniform curve now. Not perfect but close enough and much better than before. 8)
straightened1.JPG
 

hairymick

Well-Known Member
Dec 8, 2005
2,107
2
Queensland, Australia
heya Scooter, I reckon that is good enough mate, Well done :D

Jack, it is not my bosses fault. He has done what he can. Unfortunately,
there seem to be those in higher places who delight in making life difficult.

They would be as quick to kick his arse as he is to kick mine when I am naughty.We all have our proceedures that need to be followed, even when, at times, it seems they have been created by mind numbingly stupid people.

I am sure your government agencies are little different.

Oh yeah, Scooter, sorry about the hijack mate. didn't mean to. :oops:
 

hairymick

Well-Known Member
Dec 8, 2005
2,107
2
Queensland, Australia
Love ya teardrop. Did you build it yourself?

Thinking about having a crack at something like that myself. Never seen one before. the are a little like the real early caravans we had here in the 50s only smaller and prettier.
 

stevesteve

Well-Known Member
Sep 5, 2006
111
0
UK
Hey Scooter,

Nice recovery mate!

You have pulled that back into shape better than I did. Next pirogue I am going to use your method!
 

oldyaker

Well-Known Member
Aug 26, 2003
1,949
31
Yes, I too suffer the pain and embarrassment of a wavy bottom. Tried different methods of getting them out. The log method should have been used. I was in a hurry to have the boat done for a swamp trip as well. The trip never materialized. Should have never got in a rush but I did. The boat is being glassed and some wave action is still there. I figure it's part of the learning curve since it's my first attempt at small boat building. I was going to attempt a more difficult boat project for the first boat, Chuck suggested I start with a pirogue. I'm glad I did. Hopefully I will avoid first timer mistakes on the next one.
 

VTFogg

Well-Known Member
Jan 14, 2007
73
1
Rutland, Vermont
Uh, oh. I've got this same problem now. In my case it is all between the center and outer ribs, especially close to the center rib where the joint section flares inward. I've only dry fitted the ribs with screws, and the rub rail is just clamped on.

Mick, you were right about dry fitting everything first to make sure it is as expected.

- VTFogg