Curved Ply Part For Campervan, Help!

[I like Ply]

Hello,
My name is Toby,
I am a product designer currently building a campervan.
I have lined the campervan with 9mm hardwood ply on the walls and ceiling, and wanted to make a curved transition between the two.

The idea I have come up with to steam bend a piece of 9mm with grooves cut into it. The grooves were cut because I only had a kettle to steam bend them, and so the less ply to bend, the easier.
I have found that using a kettle is barely sufficient to bend this ply evenly, and works best when the grooves are showing, as the grooves close up and prevent one section from bending more than another.
I would prefer to have the smooth uncut ply veneer on show, but without a wood steamer I think it unlikely.

I'm sure there are better ways, for example building a mould, then using glued veneers in vacuum bag.
I would prefer not to have to build the mould and invest in vacuum forming apparatus, or in building a steamer etc.

I am hoping someone might be able to help!
Any suggestions more than welcome, Thanks!

 

[worn thumbs]

There are several approaches that would work.If the sides are straight and parallel,it would allow you to use a constant section.Since you don't have vacuum equipment you can't get away with making one half of a former and laminating from three skins of 3mm plywood.You may be able to make a former for both sides and use cramps to exert the force that will allow you to laminate but it takes a bit of time and effort in spite of saving the cash for a vacuum system.
You might try bead and cove strips as used for strip built canoes and it can look very nice.The fairing and smoothing on an overhead surface won't be particularly pleasant or pain free.The most laborious method would be to buy a large enough slab to carve the inner and outer surfaces to shape,but the wastage is phenomenal.
I suppose the business of product design is focused on achieving the desired outcome with the resources on has on hand and ,put bluntly, it seems that you need more than you have.

 

[toolsntat]

Look for a product called flexiply.
Getting a match for the one you are using may be a task.
Cheers, Andy

 

[eribaMotters]

Another idea would be a contrasting overlay of brushed aluminium or stainless steel. This would match the probable SMEV hob/sink you will be using. You could also tie it in with some tambour doors on top units. This is a factory fit corner unit in my Eriba caravan to give you an idea.

Are you aware of this supplier:- Campervan Self Build Parts Shop Archives
I've used them for many years for caravan electrical sockets etc, but they offer so much more.

Colin

 

[Tris]

Just to add to the above suggestion
https://magnummotorhomes.co.uk/
And

https://www.olearymotorhomes.co.uk/shop-for-motorhome-caravan-camper-selfbuild-parts-1-c.asp
Have used both when building a campervan last year and can recommend their service

 

[Tris]

To bend your ply look for a cheap wallpaper steamer on secondhand sites. Some thick polythene and duct tape will make a simple steam chamber, or build a simple ply box.
As long as you have some simple formers to clamp the ply into once it comes out you should be able to get a decent result. I'd be tempted to steam three thin pieces at a time, then clamp them as one, glueing up in the formers once they've cooled

 

[worn thumbs]

It might be a bit hopeful to expect just any ply not to delaminate when subjected to steam.Flexiply may take the curve if applied in a few laminations but I haven't been too impressed by the surface quality when a clear finish is applied,but I suppose a veneer could be added.

 

[Inspector]

You have the kerfed plywood in place now so presumably you can get it out as is. With that in mind I would work thickened epoxy into the kerfs even if only every few inches. When it sets you can take it out, fill the rest of the grooves if you like, then sand and fair as needed. Now you can glue veneer to it by whatever means you are comfortable with. I would also put a few more kerfs in it to make the bending easier, maybe making them a little deeper.

Pete

 

[Inspector]

One more option to look into.

If your radius is constant from end to end you could get a plastic pipe like PVC and cut out the section from it, scuff the inside and then glue (probably epoxy) the veneer to the inside. A printed woodgrain transfer could work too. The PCV can be manipulated some (open, tighten or twist the radius) with a heat gun to fit better. Might also be able to the same with other plastic sheet if you want some flat before transitioning into the radius. Shims in behind would make up the thickness differences and the existing plywood.

Pete

 

[Ollie78]

Use two layers of thinner ply one on top of the other glued with pu glue. This way it will not need steaming.

 

[HOJ]

If your radius is constant from end to end you could get a plastic pipe like PVC and cut out the section from it

What about using plastic guttering, and:

scuff the inside and then glue (probably epoxy) the veneer to the inside.

You could have it so it covers the side wall and roof joint, will leave a joint line, but a lot easier to be honest about it rather than try to hide it.

I am a product designer

No offence, but the last time I had a job from a "product designer" he wanted me to work to 0.1mm tolerance on a bespoke wood unit, got it close, then went to install and we had to absolutely butcher it to get it to fit, just saying..

 

[Jameshow]

I'd use veneers and make your own plywood?

Or get some cheap Chinese? plywood and soak it so it comes apart and re glue with titebond or polyurethane glue?

Just a thought!

 

[mc281]

Hello,
My name is Toby,
I am a product designer currently building a campervan.
I have lined the campervan with 9mm hardwood ply on the walls and ceiling, and wanted to make a curved transition between the two.

View attachment 174088View attachment 174086

The idea I have come up with to steam bend a piece of 9mm with grooves cut into it. The grooves were cut because I only had a kettle to steam bend them, and so the less ply to bend, the easier.
I have found that using a kettle is barely sufficient to bend this ply evenly, and works best when the grooves are showing, as the grooves close up and prevent one section from bending more than another.
I would prefer to have the smooth uncut ply veneer on show, but without a wood steamer I think it unlikely.

I'm sure there are better ways, for example building a mould, then using glued veneers in vacuum bag.
I would prefer not to have to build the mould and invest in vacuum forming apparatus, or in building a steamer etc.

I am hoping someone might be able to help!
Any suggestions more than welcome, Thanks!

My father and I (Dad is no longer alive) built a canal boat with curved roof linings, forming the curve in a mold and then lining the ceiling surface with Formica (Melamine nowadays) sheeting. It looked superb and won best home built boat in the UK 3 years in a row (IWA Nationals) in the 1970s.
We built it with the hope that it would give 10 years good full summer-time use when he retired in 1971.
It was sold only a few years ago, still in perfect condition.
I would use the same curved ceiling molding method again.

 

[worn thumbs]

Use two layers of thinner ply one on top of the other glued with pu glue. This way it will not need steaming.

The springback will be considerable with only two layers.Back in the 80's I made a section a bit like a question mark from 4 layers of 1.5mm birch ply and it held it's shape quite well.

 

[Ollie78]

The springback will be considerable with only two layers.Back in the 80's I made a section a bit like a question mark from 4 layers of 1.5mm birch ply and it held it's shape quite well.

You could be right, I was thinking it would be built in situ and sort of fixed as it is built.

 

[niall Y]

A different era, but this might be of interest:
https://www.larp.com/legioxx/scupress.html

 

[Tris]

A different era, but this might be of interest:
https://www.larp.com/legioxx/scupress.html

Did a double take there, then put my glasses on. Thank god it didn't say what I first thought. Ouch

 

[Jameshow]

My father and I (Dad is no longer alive) built a canal boat with curved roof linings, forming the curve in a mold and then lining the ceiling surface with Formica (Melamine nowadays) sheeting. It looked superb and won best home built boat in the UK 3 years in a row (IWA Nationals) in the 1970s.
We built it with the hope that it would give 10 years good full summer-time use when he retired in 1971.
It was sold only a few years ago, still in perfect condition.
I would use the same curved ceiling molding method again.

We need more pictures!

 

[cerro]

Use 1/8 cheap ply and glue them up to the thickness ether in sito or on a mould the last sheet a nice looking sheet of ply.

 

[TRITON]

Seems like the perfect opportunity to me to justify fully buying a bagpress system.
https://www.axminstertools.com/bagpress-minipress-mk2-vacuum-press-951656

Cheaper option if you already have a 1or2hp compressor
https://www.axminstertools.com/bagpress-bppn21-vacuum-kit-211938