Which wood?

[Andy CParticipant @andyc56856]

Hey all

 

I have just bought an other popular model boat mag because they were doing a couple of free plans. I now have a great set of plns built up this way.

One is for a Vosper Covette and it says to build out of Balsa.  When looking at the pics of the build, the finish does not look that great.  Can I build using 3mm or so marine ply?  Would this be a better material to use and give a better finish or should I stick to the balsa?

 

Any opinions welcome.

 

Regards

Andy

[Andy CParticipant @andyc56856]

[neil hpParticipant @neilhp]

i always like to plank in obeche…..sands well, close grain and a lovely finish too.

neil.

[Paul TParticipant @pault84577]

Andy

 

Neil is bang on with his choice of obeche, its better than ply for planking and easier to use than timbers such as mahogany….always opt for a close grain timber and never use pine.

 

Paul

[Andy CParticipant @andyc56856]

Hi Paul, Neil

 

It is not for planking but for a the whole model.  It is a very simple build, the sort I need at the moment, and it is used to make the hull bottom and sides, plus the lift off super struture.  It just seemed to me to be a very poor finish for the model.

 

Andy

[Bob Abell 2Participant @bobabell2]

Hello Andy

 

I would use 3mm liteply, for the complete build

 

Balsa is difficult to work with, unless you tissue cover it, to fill the grain?

 

Bob

[Paul TParticipant @pault84577]

Andy

 

3 or 4 mm ply is the best but try and find 5 core sheets rather than 3 core.

 

Paul

[Andy CParticipant @andyc56856]

Great thanks for your help. I will look into 5 core stuff.

 

Regards

Andy

[Andy BaileyParticipant @andybailey80218]

A very sensible question , while reading through i wondered how many years of experience was called upon for the answer to this post ??

Just goes to show how vital these forums are for all modellers ,, better than any book i know of !

Good luck with the build Andy keep us informed 

Andy

[Tony HadleyParticipant @tonyhadley]

Paul,

 

Couldn’t help but notice your comment  ‘always use a close grain timber and never use pine’.

 

Why avoid pine? — the reason why I ask is, I considered building the Maltese “Luzzu”, which came as free plan in January 2009 MMI. The original model featured in the magazine item advises the use of pine (piranah, recovered from old furniture), for the ribs and planking.

 

Thanks,

Tony.

[neil hpParticipant @neilhp]

pine these days is “force grown” quickly and has a very open, “wavey” grain, with little substance or texture……70% water content. and always prone to warpage and shrinkage.

 

where as older  pines used for building such as yellow and piranah pines were a slow grown and natural seasoned timber giving a much closer grain and virtually water free due to length of time in natural seasoning, and as such much nicer to carve, cut and plane, as well as sanding and finishing.

That is why pattern makers used to use yellow and piranah pine for making patterns for casting and moulding.

hope this helps.

 

mind you to find yellow and piranah pine is like looking for the opt of gold at the end of the rainbow.

neil.

[Paul TParticipant @pault84577]

Nothing to add to Neils comments only to say that if I wanted piranah pine then I would be searching the building salvage yards for old panel doors.

[Andy CParticipant @andyc56856]

It seems choosing the type of wood is not a simple thing.  Different grain, different types of wood etc.  I will have a look in my local model shop but I think it might be a case of going to a timber yard.  Not sure I’ve seen ply in local shop, only balsa.

 

 Andy

Edited By Wraith Leader on 04/12/2009 07:40:53

[Colin BishopModerator @colinbishop34627]

When I first started modelling using bread and butter construction techniques, yellow pine was the recommended material as being ideal to work with an carve. It was expensive even then and I had to settle for Parana Pine (Piranahs bite!)  which was considered to be second best as it suggered from knots and was more inclined to split. You could get hold of it quite easily though.

 

When you think about it, bread and butter construction was not a very planet friendly method. You buy a whole load of planks equal to the volume of the hull you want to make, then you cut out all the inside and most of the outside so you’ve maybe got 5-10% of the original material going into the hull. I remember that a fellow modeller was appalled at this wastage at the time and worked out a method of drawing the finished shape of each “plank” with the inside and outside cut away. These shapes where then split down the middle to give two “bow” shaped sections. It was then possible to arrange these sections on a full sized plank shape, nesting them inside each other to minimise the wastage. It was very ingenious and for one model he managed with just two planks. One provided the bottom of the hull and the other the sides. happy days!

 

Colin

[Glynn GuestParticipant @glynnguest59245]

Wraith Leader,

Returning to your original post, I think I saw the plan article you mentioned. Yes, like you I thought the finish on a balsa hull looked ghastly.

The only reason for such a poor finish is the lack of knowledge, effort or the desire to produce a smooth surface.  Over the years cellulose dope (neat, thinned or bulked up to make “sanding sealer”) has served me well.  Several coats, sometimes with a layer of tissue paper, ought to make a balsa surface fit for painting.

True, balsa does not make an indistructable hull but if you abuse your models then I doubt that any material will satesfy you.  With reasonable deign and construction standards, balsa hull can be built quickly and ecconomically.  I’m still sailing such hulls that are into their fourth decade!

Glynn Guest

[Andy CParticipant @andyc56856]

Hi Glynn

 

Thanks for the comments, I think I have your plan for the Goblin somewhere too, this was ply, if my memory serves me.  I think the Vosper can be done with 3mm ply, so I may give that a go.  Still thinking of doing the Goblin as well.  Either would be a good boat for my young ones.

 

Andy

[Glynn GuestParticipant @glynnguest59245]

Wraith Leader,

                        By all means try 3 mm plywood but you may find that it becomes something of a struggle when building smaller models.  “Liteply” might be easier but you will still have a quite open grain surface to fill and seal.

Good luck

GlynnGuest

[neil hpParticipant @neilhp]

 Parana Pine (Piranahs bite!)  

 

it always had teath when I used to try and plane it, Colin, lol

[hammerParticipant @hammer]

After the second world war the supply of yellow pine was almost nonexistant, that is when pirana pine started to become popular, a very poor substitute. It is unstable in length as well as width,most unusual in timber. About is only asset the lack of knots.

Yellow pine is best found today in prewar pannel doors look in builders skips. Balsa is ideal for models. I have a 5ft long hull built of 1/6″ balsa covered in ali drink can plates, it has been droped from a hight of 4ft and is 9 years old, still as good as new. If I had impregnated the inside with resin it would be even better. But I was new to boats at the time. R.G.Y. 

[Author]

Posts