Topic: Which to use and when (lite ply vs birch ply) (Read 8475 times)

glyn44 · « **on:** February 04, 2018, 04:32:33 pm »

Looking at various boat plans I have noticed that two common plys are often called upon. One is lite ply, and the other birch ply. I am unsure what the difference in characteristics are between the them, and which to select for what jobs.

I can see that there is a marked difference in surface finish, but often this is not exposed to the eye when the model has been completed.
Regards G44

ballastanksian · « **Reply #1 on:** February 04, 2018, 05:50:17 pm »

A quick look on t'internet (RC Groups so far) suggests that Lite Ply is made from softer timber such as Poplar rather than Birch, and it can have fewer laminations than Birch ply, but this latter statement surely varies with the thickness of the board.

Further down, a member says that higher spec white goods shipped from Italy (Big manufacturer of electronic gubbins) are clad in liteply for protection, so asking your local appliance shop might get you free or cheap liteply packaging?

unbuiltnautilus · « **Reply #2 on:** February 04, 2018, 06:17:50 pm »

Lite ply is, by definition, lighter than normal ply. It is easier to cut and sand, more like balsa than normal ply, but it has acoarser surface finish that would require more preparation if being used as an external surface on a model. I have used it in the past to build an entire 32" x 12" crane barge, which did sterling service for a couple of years, before I passed it on to a ham fisted oaf, who still managed to get at least three more years use out of it! This was all down to preparation and protection of the timbers. The insides of the model were coated in Cascamite, while the outsides had multiple coats of cellulose sanding sealer, followed by enamel top coats.

These days I mostly use it for internal work, bulkheads, battery trays etc. In fact over on 'Warships', I am about to use some on my Perkasa rebuild, internally, and clad in 1/32" ply for a decent surface finish. There you will note that I am using normal, denser plywood for the deck infills, rather than the lite ply. They both have their uses.

glyn44 · « **Reply #3 on:** February 04, 2018, 06:43:45 pm »

Ok birch ply is sturdier and does have better surface finish as I understand you both correctly. I also noticed this afternoon that the birch seems to be available in lesser thicknesses than the lite ply. So that’s probably another consideration of the design specifications.

Many thanks for your time.

Brian60 · « **Reply #4 on:** February 04, 2018, 07:09:01 pm »

Liteply is the stuff you get from that large diy chain with 2 initials. Easy to cut as it only has 3 ply's two outer and a thicker inner, in thicknesses 5 mm and up - Iv'e never seen it in less.

Birch ply has lovely smooth surfaces on both sides and even down to tiny thicknesses (1/16th as sold in model shops) and has 5 ply's. At some point in thickness I think over 6mm this undergoes a further treatment and is known as marine ply (but I could be wrong) Birch ply is also the favoured type of ply for laser cutters as it comes out nice and crisp, liteply burns way too easily and gives a poor finish in a laser cutter.

edit: should also add that over 6mm with birch ply the number of ply's also goes up, 7,,9,11 etc

glyn44 · « **Reply #5 on:** February 04, 2018, 07:24:17 pm »

Well explained Bran, thank you. But you can definitely get thinner ply here:

http://www.slecuk.com/balsa-wood/2.0mm-Lite-Plywood.html

unbuiltnautilus · « **Reply #6 on:** February 04, 2018, 08:30:54 pm »

Quote from: Brian60 on February 04, 2018, 07:09:01 pm

Liteply is the stuff you get from that large diy chain with 2 initials. Easy to cut as it only has 3 ply's two outer and a thicker inner, in thicknesses 5 mm and up - Iv'e never seen it in less.

Birch ply has lovely smooth surfaces on both sides and even down to tiny thicknesses (1/16th as sold in model shops) and has 5 ply's. At some point in thickness I think over 6mm this undergoes a further treatment and is known as marine ply (but I could be wrong) Birch ply is also the favoured type of ply for laser cutters as it comes out nice and crisp, liteply burns way too easily and gives a poor finish in a laser cutter.

edit: should also add that over 6mm with birch ply the number of ply's also goes up, 7,,9,11 etc

I don't think The Place That Shall Not Be Named actually sell what is called Liteply, I think they have a brand referred to as S***ply ( speaking from past experience! It is better now, but even now, who needs a micro thin laminate of posh looking wood on the exterior, that flakes off with the first cut! Rather it wasn't there in the first place!! ).
Liteply as I understand it is intended for model aircraft use and is usually available in sizes from 3/32", 1/8" up to 1/4". Birch ply goes right down to 1/64" or 0.4mm, and that still has three layers, incredible! Mind you, that is reflected in the current pricing, I feel it would be cheaper to apply a 1/64" layer of gold rather than 1/64" plywood at the moment!

Colin Bishop · « **Reply #7 on:** February 04, 2018, 08:44:13 pm »

Horses for courses as usual.

I am a fan of birch ply as I much favour it over plasticard. It takes a great finish.

However I am currently building a kit review model for a magazine which features 2mm and 3mm liteply and the material is ideal for the project with its combination of strength and easy shaping. Yes, it does need to be properly sealed, in this case with lightweight glass cloth and resin. As always it is a case of matching suitable materials to the project in hand.

Colin

unbuiltnautilus · « **Reply #8 on:** February 04, 2018, 09:45:48 pm »

Quote from: Colin Bishop on February 04, 2018, 08:44:13 pm

Horses for courses as usual.

I am a fan of birch ply as I much favour it over plasticard. It takes a great finish.

However I am currently building a kit review model for a magazine which features 2mm and 3mm liteply and the material is ideal for the project with its combination of strength and easy shaping. Yes, it does need to be properly sealed, in this case with lightweight glass cloth and resin. As always it is a case of matching suitable materials to the project in hand.

Colin

Absolutely. My current build is almost entirely a combination of plywoods and balsa, which is my favoured material. My next project will be all plasticard ( don't like the stuff, must get over it. Best way to do that, build something with it! ).

glyn44 · « **Reply #9 on:** February 05, 2018, 07:57:14 am »

I still am unsure of what, if any, are the structural differences I should consider, not in the manufacturing of the ply, but when deciding which to use on a model. That is to say is there any advantage of one type over the other when making a particular component for a boat? I.e which is the stronger for identical thicknesses. My crude testing says not a lot.

unbuiltnautilus · « **Reply #10 on:** February 05, 2018, 09:29:32 am »

Each model will vary. I would suggest a boxy structure, like a springer or landing craft could use either birch or lite ply throughout. It will be a stiff structure anyway. A hull that requires some stressing in the build, i.e. requiring planking or ply skins forced round the form to fit, may benefit from stiffer birch ply for its keel and frames. A small fast speed boat or a hovercraft could be entirely built using a combination of lite ply and balsa. Superstructures would benefit from the lightness of the light ply, but thinner grades of birch ply would also be suitable.
I would guess that just made things more complicated.....glad I could help

boat captain · « **Reply #11 on:** February 05, 2018, 09:36:22 am »

I have always understud lite ply is laminated balsa wood.

unbuiltnautilus · « **Reply #12 on:** February 05, 2018, 09:39:28 am »

Quote from: boat captain on February 05, 2018, 09:36:22 am

I have always understud lite ply is laminated balsa wood.

It doesn't look like it, but I have heard reference to 'balsa ply' in American publications. Its inner laminate may be balsa, I shall rip some apart and have a look.

unbuiltnautilus · « **Reply #13 on:** February 05, 2018, 09:42:52 am »

It is a pink coloured outer laminate, with what does look like a hard balsa core. Difficult to tell with only a skinny laminate to work with, but it does look like a balsa inner lamination.

tigertiger · « **Reply #14 on:** February 05, 2018, 10:06:59 am »

***Topic name modified***
To help with searches in the future.

Tug Fanatic · « **Reply #15 on:** February 05, 2018, 11:31:27 am »

I am sure that a lot of different products are available under the general heading of Lite ply (some I am guessing are wonder products

) but to me the big difference with birch ply is that whilst lighter & cheaper Lite Ply does not like getting wet. That is it really hates getting wet.

I would not use it on the outside of a model unless I was going to cover it in fibreglass cloth & unthinned epoxy resin on the outside & at least unthinned epoxy resin on any inside surfaces & into any joints etc. This can be very difficult to achieve with multi deck superstructures.

The big use that I have seen for it is in caravans where weight is important but I have also seen what happens when water (damp) gets into it. I cannot guarantee that my models never get damp so I find it hard to justify using it.

Liverbudgie2 · « **Reply #16 on:** February 05, 2018, 12:43:59 pm »

The "Liteply" as found in model shops is made up of a balsa core covered in "obechi " (sp). "Marine Ply" or "outdoor ply" as sold in shops and timber yards, is ruddy awful stuff to work with and splinters just by looking at it; neither is it "lite" I avoid using this stuff like the plague for any job.
Real "Liteply" is very nice to work with on flat straight objects such as superstructure sides but, it does not bend easily, if at all. It also should be sealed if used on models as mentioned above. I used it to build up the superstructure of a destroyer where top weight was important, this was then covered in "cross cut" 1/64" aircraft Ply. The importance of the ply being cross cut was that it would easily go around a radius. However, on cost grounds this route is now prohibitive to a lot of people I should think.
In light of this, I have been considering using copper clad board for superstructures and alike. It's not that cheap but, it's a lot cheaper than real marine ply of a similar thinness and easier to work with., so I'm told. For instance, a lot of the detail work that you see on models at the Dortmund show are built from this material.

LB

Tug Fanatic · « **Reply #17 on:** February 05, 2018, 12:58:46 pm »

Quote from: Liverbudgie on February 05, 2018, 12:43:59 pm

...............................................In light of this, I have been considering using copper clad board for superstructures and alike. It's not that cheap but, it's a lot cheaper than real marine ply of a similar thinness and easier to work with., so I'm told. For instance, a lot of the detail work that you see on models at the Dortmund show are built from this material.

LB

I am guessing that by this your mean printed circuit board which I cannot fond for less than £25 sq/ft. Have you considered smooth finished smooth finish epoxy G10 sheet which is much cheaper at around £10 sq/ft & I would have thought better. The link that I have given is not necessarily the cheapest but gives an idea of what I mean.

https://www.ebay.co.uk/itm/Epoxy-Glass-Fibre-Sheet-GRP-G10-FR4-Glassfibre-A4-Plate-0-5mm-1mm-1-5mm-5mm-10mm/122308278979?var=422797858541&hash=item1c7a243ac3:m:m0EAs-TCZZnCs8SG3IR5epA

I have been considering this:

https://www.ebay.co.uk/itm/2mm-White-Matt-Foamex-Foam-PVC-Sheet-9-SIZES-TO-CHOOSE/282545530337?hash=item41c906a5e1:m:moCKfK0-_S5TbfggzE0BSWw

barriew · « **Reply #18 on:** February 05, 2018, 01:45:45 pm »

Quote from: Tug Fanatic on February 05, 2018, 12:58:46 pm

I have been considering this:

https://www.ebay.co.uk/itm/2mm-White-Matt-Foamex-Foam-PVC-Sheet-9-SIZES-TO-CHOOSE/282545530337?hash=item41c906a5e1:m:moCKfK0-_S5TbfggzE0BSWw

I have used this once - its easy to cut, but difficult to stick I found.

[size=78%] [/size][/size]I ended up using some plumbers solution if I remember.[size=78%]

[/size]Barrie[size=78%]

Liverbudgie2 · « **Reply #19 on:** February 05, 2018, 01:53:58 pm »

Quote from: Tug Fanatic on February 05, 2018, 12:58:46 pm

I am guessing that by this your mean printed circuit board which I cannot fond for less than £25 sq/ft. Have you considered smooth finished smooth finish epoxy G10 sheet which is much cheaper at around £10 sq/ft & I would have thought better. The link that I have given is not necessarily the cheapest but gives an idea of what I mean.

This is what I was looking at: https://www.ebay.co.uk/p/203-X-305mm-Copper-Clad-PCB-Fr2-Laminate-Single-Sided/1388325733?iid=140916335191&_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D2%26asc%3D49919%26meid%3D319f5644b764472d8f9aa73c3d562364%26pid%3D100005%26rk%3D5%26rkt%3D6%26sd%3D263140927564%26itm%3D140916335191&_trksid=p2047675.c100005.m1851

This works out at being about 12"x8" as far as I can see for £3.75. So a lot less than £25 per.sq foot but there again I'm no mathematical genius, far from it in fact!

LB

Tug Fanatic · « **Reply #20 on:** February 05, 2018, 02:20:16 pm »

Quote from: Liverbudgie on February 05, 2018, 01:53:58 pm

This is what I was looking at: https://www.ebay.co.uk/p/203-X-305mm-Copper-Clad-PCB-Fr2-Laminate-Single-Sided/1388325733?iid=140916335191&_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D2%26asc%3D49919%26meid%3D319f5644b764472d8f9aa73c3d562364%26pid%3D100005%26rk%3D5%26rkt%3D6%26sd%3D263140927564%26itm%3D140916335191&_trksid=p2047675.c100005.m1851

This works out at being about 12"x8" as far as I can see for £3.75. So a lot less than £25 per.sq foot but there again I'm no mathematical genius, far from it in fact!

LB

That is very inexpensive. Well found.

Tug Fanatic · « **Reply #21 on:** February 05, 2018, 04:31:19 pm »

Quote from: barriew on February 05, 2018, 01:45:45 pm

I have used this once - its easy to cut, but difficult to stick I found. I ended up using some plumbers solution if I remember.Barrie

[size=78%]

The USA forums swear by Foamex & superglue without kicker.[/size]

RST · « **Reply #22 on:** February 05, 2018, 09:42:03 pm »

As unbuiltnautilus said BnQ or diy stores don't sell liteply. Liteply is a perfectly good light and strong material and many, many model aircraft are built using it. There's not really much wrong with diy store materials (apart from MDF though some do use it OK), particularly as allot of folk cover with polyester resin anyway, as long as you handle it right and expect reasonable results for the price.

Tug Fanatic · « **Reply #23 on:** February 06, 2018, 07:51:40 am »

Quote from: RST on February 05, 2018, 09:42:03 pm

..................... Liteply is a perfectly good light and strong material and many, many model aircraft are built using it.......................

True - but most model aircraft are not expected to get wet.

Stan · « **Reply #24 on:** February 06, 2018, 08:37:44 am »

Simple answer stick with normal ply for any external work. I used lite ply for part of my latest build it took forever to seal the grain. I would only use it for parts that are not having to have a finish applied. On the positive side it is a easy material to work with hope all goes well with your project.

Stan

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Author Topic: Which to use and when (lite ply vs birch ply) (Read 8475 times)

RST