[Keeper]

I am in the process of building seats for my t-bucket project. Since I have no umm padding on my rearend I will be using webbing to help cushion the ride.

My question is - How much do you stretch the webbing when installing it? Is there a standard such as - stretch 1/4 inch for every inch of cut length? or is it more of a "How firm do you want it" kind of thing?

I am documenting the entire process from start to finish, I am currently here:
There is a 4 inch border around the seats, leaving 8inches in the middle, I plan on creating a fold down armrest for the center.





I am planning on using marine vinyl with 3/8 sewfoam, 2 inch c45 foam base, 1 inch c45 foam for sculpting, on the back I am using a 1 inch c45 for the base, and c35 for the sculpting.

Once everything is done, I will try and post up a step by step.

Thanks.

[DanTwoLakes]

First of all, you really need bigger openings, or all you'll be doing is sitting on the plywood, and the webbing won't have any effect. I would leave 2 1/2" around the perimeter and 5" in the middle. That's plenty with a 3/4" plywood base. It needs to be supported on both ends and in the middle. 3" of 45 compression foam is an absolute minimum. If you're a big guy that wouldn't be enough.

What kind of webbing do you have? It looks like back webbing and not seat webbing. 3" wide #7 seat webbing only stretches about 5%, 2" wide #6 seat webbing stretches 20%, and 2" wide #2 back webbing stretches 90%.

There is no rule of thumb for how much to stretch the seat webbing, but you can only stretch it so far. Pull it tight, but don't go crazy. If you don't stretch it enough you defeat the purpose too.

[Keeper]

Okay lets see.

I can adjust the openings with out issue.

The 5 wedges you see in the pic are the seat supports, one on each side of the openings and one right in the middle.

I was told the webbing was seat webbing, but after seeing in another one of your posts to look for the redline down the middle, I will go back and see if the upholstery shop has the red.

Adding more foam on the bottom should not be an issue, I bought plenty of extra!

Go to know on the stretch.

Thanks.

[Keeper]

Oh yeah,

Thanks for all your contributions on this forum, I have spent days reading through your threads. It has and will help me throughout the build process.

[DanTwoLakes]

If you have seat webbing, it should not stretch much. If it's back webbing, it stretches very easily. The red line is really only for the brand of elastic webbing called Intes Elasbelt. If you have another brand and it is actually seat webbing that's fine.

[Keeper]

Thanks,

I called the shop I got the webbing from, they told me that's all they use for seat bottoms. I won't say its hard to stretch, but it is certainly not easy.

If it proves to be to soft, not that I can see that happening, I can always redo the webbing.

Another question is, spacing on the webbing? I was planning on weaving them and running with about a 1/4 inch spacing.

I also plan on covering the webbing with some vinyl prior to adding foam, figure it should help the foam live a little longer. I know some folks use burlap. Any other things to consider?

[lakeroadster]

Here is how I did my '27 RPU. Same concept as you but I only left about 1-1/2" of plywood around the edge, then crossed the elastic material.





Originally I was planning to use springs:


My upholsterer talked me into foam. My butt wishes I would have used springs for the bottom....... I am thinking about redoing the base to use the springs.

[Keeper]

Very nice. The pics help a ton.

How is that short windshield?

[lakeroadster]

Originally Posted by Keeper

Very nice. The pics help a ton.

How is that short windshield?

It's great! I actually look over the top of it (I am 6' tall), but the wind hits me just about at the top of my head.

[DanTwoLakes]

Originally Posted by Keeper

Thanks,

I called the shop I got the webbing from, they told me that's all they use for seat bottoms. I won't say its hard to stretch, but it is certainly not easy.

If it proves to be to soft, not that I can see that happening, I can always redo the webbing.

Another question is, spacing on the webbing? I was planning on weaving them and running with about a 1/4 inch spacing.

I also plan on covering the webbing with some vinyl prior to adding foam, figure it should help the foam live a little longer. I know some folks use burlap. Any other things to consider?

The spacing doesn't have to be that close together. I leave about 2" in between the rows. There's no point in putting the webbing really close together, it doesn't help and it wastes a lot of webbing. You can cover the webbing with anything that will keep the foam from being pushed down through the gaps. It doesn't have to be very thick. I use Versare, which is something like typar landscape fabric.

The problem with the urethane rubber webbing Lakeroadster used is that over time it gets hard and brittle and loses its elasticity.

[Keeper]

After working on the seats some more today, I realized this webbing has to be for the back. I strung a couple runs across the bottom and even if I pulled it tight there was still over an inch of movement.

So I put the bottom on hold until I can get some webbing, hopefully tomorrow.

Here are some progress pics:

I took your recommendation and cut some more wood out of the base:




Then I started on the back:

Once I cut the first piece, I set it in place and realized it wasn't going to work at the angle I wanted. So I used it to make a template:



Then I cut out the back, I plan on webbing the back as well, so I measured that out and made the cuts:


Now for the upper part of the back, I borrowed some ideas from chair making, you can see the hard board I used for the template in the last pic. I then cut the plywood to rough shape and glued it all up. Tomorrow I will finish the shape and carve out the reliefs at the top:

This is where I stopped for the night.


I did not mean to turn this into a step by step post, once I am finished I will do up a full on post.

[DanTwoLakes]

Seat webbing is usually about an eighth of an inch thick, and back webbing is usually thinner than that. What are the four pieces of plywood you are gluing together for?

[Keeper]

Those are for the shaped back section. Here is the end result of the frame:



I played around with different foams, thicknesses and placements last night while watching the hockey game. Pretty comfy.