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Lightest plywood
lsdweb - 7/11/10 at 10:09 AM

Hi all

This is car related honestly :-)

I'm looking for the lightest plywood I can get for the dash of my 26R rebuild. - needs to be about 10mm thick. I've got a dash (3 ply) but it's pretty unique so I need to build a new one. The original is light as hell!

I'm sticking to wood as aluminium and c/f just don't look right in a historic car. I haven't decided on a finish yet - possible just black paint or a veneer finish (as per the originals)

Any thoughts


2cv - 7/11/10 at 10:17 AM

Lotus Elan?


iank - 7/11/10 at 10:24 AM

If the original is very light at 10mm then it's probably a marine product with a balsa wood core.


interestedparty - 7/11/10 at 10:26 AM

Light plywood = cheap plywood, usually
Cheap plywood = small number of laminations, very rough cutting

The best way to do this would be to get some decent thin plywood (you will NOT be able to do this at a timber yard/B&Q etc). Model shops are good sources, or anyone who uses birch plywood might have some offcuts. Anyway, thin plywood of say 6mm thick, make up the whole dash, then cut extra layers just for where it needs to be thicker, (cut outs, fixings etc) and glue them on. Then, of course a layer of veneer.

To get the thick, varnish look of older cars you really need polyester lacquer, not DIY stuff, auto restoration suppliers might have an epoxy based alternative.


rf900rush - 7/11/10 at 10:34 AM

Try the Model plane world.

A product often called Lite Ply is used.

Not sure how large or thickness you can get.
May be worth a look.


liam.mccaffrey - 7/11/10 at 10:35 AM

Possibly make up your own lamination with veneer and a balsa sheet core? Not sure how structural it needs to be


Dave Ashurst - 7/11/10 at 11:01 AM

quote:
Originally posted by interestedparty

The best way to do this would be to get some decent thin plywood (you will NOT be able to do this at a timber yard/B&Q etc). Model shops are good sources, or anyone who uses birch plywood might have some offcuts. Anyway, thin plywood of say 6mm thick, make up the whole dash, then cut extra layers just for where it needs to be thicker, (cut outs, fixings etc) and glue them on. Then, of course a layer of veneer.

To get the thick, varnish look of older cars you really need polyester lacquer, not DIY stuff, auto restoration suppliers might have an epoxy based alternative.




Seconded. I think that's what I'd do. I have some smiths gauges on a Triumph dashboard that was clearly made like that.

Alternatively (because I'm lazy) perhaps I'd try making a 10 or 12 mm marine ply blank and router out the back to lighten it, leaving a skeletal frame with a complete face.


Surrey Dave - 7/11/10 at 11:07 AM

Birch Ply? , used extensively in speaker cabinets.


Neville Jones - 7/11/10 at 11:57 AM

I did some work a little while ago on a mates yacht, Dehler 36, and was given pieces cut from 10mm 7 ply, that was the lightest ply I've ever encountered. The middle plies were oriented at 60 and 30 degrees.

This ply was made from aircraft grade spruce, I'm told, so the aircraft world is where I'd be looking.

There's a few diy aircraft forums, so you might want to ask on them. I'm sure you'd get an offcut the size you're looking for for not too much money.

Cheers,
Nev.


v8kid - 7/11/10 at 12:10 PM

I'd go for the sandwich construction I used something similar for my hovercraft and it is unbelievably light, extremely rigid but not as strong as the rigidity leads you to expect.

In your case I suspect it is rigidity rather than strength you need. The rigidity is proportional to the spacing between the skins and the strength proportional to the thickness of the skins.

You really need a press to glue the skins to the lightweight core.

You should be able to get a 10mm (3/8 cos of the USA market) foam core and stick 1mm skins on either side giving a total of 12mm. Rigid enough to walk on but when it goes it goes without warning.

Interesting project!


austin man - 7/11/10 at 12:23 PM

Make it in alluminium and spray with the wrinkle finish paint it will look like an early MG midget dashboard effect. so you will get both lightness and a period effect


Confused but excited. - 7/11/10 at 01:09 PM

A lot of modellers use Balsa wood coated with superglue. This results in a very light, strong material with a hard surface.
You could try making you dash from Balsa and then painting the finished shape with super glue.


Thinking about it - 7/11/10 at 02:14 PM

link


Canada EH! - 7/11/10 at 04:03 PM

Aircraft Spruce and Speciality, USA


jacko - 7/11/10 at 07:18 PM

Malaysian ply also known as Tiger wee wood


alistairolsen - 8/11/10 at 10:18 AM

Id be getting some veneer and making my own with a balsa core and epoxy personally.


stevegough - 8/11/10 at 10:55 AM

Just a thought - a lot of instruments / switches won't fit into anything that thick....


lsdweb - 9/11/10 at 09:32 AM

Thanks guys.

Plenty to think about!

And I'm still trying to decide whether to mount the fuse boxes, relays and dash loom to the dash or bulkhead.

W


lsdweb - 13/11/10 at 09:29 AM

quote:


Just a thought - a lot of instruments / switches won't fit into anything that thick....





Lotus used to route out the back of the dash panels to get the bits to fit.

I found a really light sheet of ply in B&Q of all places. Will give it a try. And it was big enough to make 3 so if I get the first one wrong.....

Wyn