How to steam balsa

[Andy BarkerParticipant @andybarker11470]

I want to use sheets to do the hull on my 18 inch brave border. However the curve at the bow is quite severe, so thought of steaming the sheet. Problem is I no idea how to steam.

Do you put wood over kettle while it boils then bend and hold… Any way I need an idiots guide. Tried searching site, can't find anything. YouTube seems to all be furniture or bigger stuff.

Idiots guide please.

[Andy BarkerParticipant @andybarker11470]

[Dave Cooper 6Participant @davecooper6]

Hi Andy,

I've not tried this myself, but I have heard others say :-

1. Clamp one end of the wood to the bench – with the bit you want to bend over-hanging.

2. Hang a weight on the over-hanging bit

3. Use a heat source (eg camping stove) on a saucepan of water and let the steam drift upwards onto the weighted over-hang. You may need to repeat this until you get the required curve.

Usual safety rules /common sense apply here…..I expect the experts will have more sophisticated methods !

Happy modelling,

Dave

[Andy BarkerParticipant @andybarker11470]

Ah, that makes sense. Thanks for that Dave. Will give it a try if I can find somewhere the wife won't complain.

[Charles OatesParticipant @charlesoates31738]

This takes me back a good few years. There are several ways of doing it, steaming in the way you suggest works well, but I prefer to soak the wood then either shape it over a heat source, a hair dryer works well and is safer than a flame or it can be taped into place and allowed to dry.

Here is a link showing different ways of doing it.

How to Bend Balsa Wood: 4 Methods to Do It

Safety first whatever you try, working in boiling water etc can be nasty.

Charles

 

Edited By Charles Oates on 05/03/2023 12:40:03

[Andy BarkerParticipant @andybarker11470]

Thanks Charles. An idiot guide, just what I needed. Soaking and hair dryer, don't think I can cause offence doing that.

Andy

[Richard SimpsonParticipant @richardsimpson88330]

Just to throw the idea into the ring, a lot of modellers do the bow and/or the stern by carving a solid block of balsa, simply glued onto the end frame. This is generally easier to work than bending sheet.

[Dave ReedParticipant @davereed72029]

Posted by Richard Simpson on 05/03/2023 23:11:34:

Just to throw the idea into the ring, a lot of modellers do the bow and/or the stern by carving a solid block of balsa, simply glued onto the end frame. This is generally easier to work than bending sheet.

Hi Richard,

What direction would you have the grain of a carved bow block or is it not important? If laminating a bow block from thinner material (as I've seen suggested elsewhere) what would be the recommended adhesive to avoid hard lines when sanding?

Presumably it will also require serious sealing for all that open end grain?

Sorry if I've 'borrowed' your post Andy but it may be relevant to you too if you end up using Richard's carved solution.

[ashley needhamParticipant @ashleyneedham69188]

CI avoid using balsa due to the very issue of grain filling. If using a block, I cant imagine it makes too much difference which way the grain is due to the 3-d nature of the carving (unless someone knows different?).

I would avoid laminating as it is very very difficult to get rid of glue lines. You can , as I have done in the past, just glue the centre of the laminations together, so that you just carve wood or Styrene, and miss the glue line.

I would use Styrofoam, as this is grain free, but is soft so does need a layer of fine glass tissue and EzeKote or something to protect it, or just be careful! Although, thinking about it, not an awful lot softer than balsaregarding dings and dents.

Saucepan of boiling water, water and a hot air gun, or simply the hot air gun all work for me on thin ply.

Ashley

Edited By ashley needham on 06/03/2023 08:26:27

[Andy BarkerParticipant @andybarker11470]

I'm going to use block balsa for the bows, the problem was with the flare of the sides before getting to the point of the bow. It's a static model so grain won't be a problem, other than finish.

The block will be glued to the forward bulkhead and centre line. Will be first time carving so think I'll be getting the dremel out.

Thanks for the suggestions.

T Pins. Someone mentioned T pins instead of sewing pins, so I got some. They are brilliant. Ah, littles things…

Andy

[Richard SimpsonParticipant @richardsimpson88330]

Have a look through some of Ray Woods superb builds. A perfect example is here:

Ray's Shandau

There you can see exactly how he has built up the bow and stern area with balsa to make carving them to shape as easy as possible.

[Ray Wood 3Participant @raywood3]

Hi All,

Thanks Richard, the cheque is in the post as usual BTW your steam boats are great !!

Laminating balsa bow blocks probably best with balsa cement, and sanding sealer to raise the grain & sand a couple of times.

Charles pretty well summed up the best method of dampen the balsa and let it dry round a bottle or jar.

My only question is how thick is the balsa sheet your using ?? anything thicker than 1/16" may not want to play !

If you only dampen one side it will expand and curl nicely anyway.

Regards Ray

[Andy BarkerParticipant @andybarker11470]

No prob Dave borrowing the thread, good info.

In the end bent the peices dry. Only 1/16 sheet. Just twiddling the sheet (as you do) whilst deciding steam, soak, hair dryer and noticed it starting to bend. snapped the first one. Recut it and being more careful found it worked. Did find though that I needed to put a couple of fillets in between the bulkhead and sheet to reenforce it.

Going to use balsa block for the bow its self. will rough cut to shape with scroll saw and then dremel and sand. If I get it right will post pics (famous last words)

Andy

[John W EParticipant @johnwe]

hi there

couple of thoughts for you with regard to building balsa wood hulls.

One of the tricks for bending balsa which had hard grain in it – lightly score the back face of the balsa in the area which you want to bend it – remember VERY LIGHT scoring across the grain or it may snap at that point. Try it out on some scrap first.

As far as blocking the bow and stern on models goes, a lot of us on this forum have done blocking in without any evidence of glue lines or anything showing through.

The one thing with balsa hulls is – you must cover them with some material and either coating it with a shrinking dope or some form of resin. On large hulls which I have built in the past, I use a lightweight cloth which the aircraft guys use to skin their planes and also use Z-Poxy to coat it with. This I feel may be extreme for an 18 inch model; there is a water based resin which everyone is using now and it is a good stuff which I suggest you use, along with tissue to cover your model. Also if you are using fillers, try to avoid using the car body fillers as it is a lot harder than balsa wood and you sometimes sand the balsa wood away before the filler. Try and use a product called Deluxe light filler. Just a couple of thoughts for you – and – I will put a couple of photographs on which may help you along, if you read Ray's postings – we should rename Ray – Speedy Gonzalas builder because of the amount of models he builds in a week – I think the ratio must be about 6-1. Ray builds 6 and the rest of us can only make 1.

John

 

 

 

Edited By John W E on 06/03/2023 16:30:46

[John W EParticipant @johnwe]

Edited By John W E on 06/03/2023 16:35:03

[Andy BarkerParticipant @andybarker11470]

Hi John

Had seem the trick of scoring the balsa, but problem being the bow curves in both planes which is quite sever on an 18" model. One to file away. Don't like the idea of using car filler either, though no doubt it has its uses. Our local builders merchant has some filler that im going to try, used on another job and found it to go hard, but not car filler hard. Interesting using aero tissue and dope to coat the hull. Will get some of the Eze-Kote and give it a try.

The bows will be two peices of block, one either side of the keel, so intend rough shaping with the scroll saw before glueing.

Ray can certainly knock them out, but with precision and a fine finish. I can only wish. Just reading Rays comment again and looking at the bows again, might be better to laminate the block. think I'll have to have a play…

Andy

[Ray Wood 3Participant @raywood3]

Hi John & Andy,

I'm always happy building something but now I have retired what's the rush ? Just trying to do a better job with Shandau which will be my last boat for a while, I have a couple of designs up my sleeve for publication in the magazine so now back onto finish 2 aeroplanes for the summer when it arrives, an electric Hawker Hurricane and a Vultee Valiant BT13 for a .90 four stroke and there is always the model railway & 5" gauge Terrier steamer so I will keep busy after I've done the housework !!

Regards Ray

[Andy BarkerParticipant @andybarker11470]

Ah Ray, the house work. Thank god for automatic washing machines. Have just glued the bow blocks so tomorrow will be curving day. Was going to go down the airplane route coming back to modeling, but they do take up a lot of room and have to consider 'she who must be obeyed' (If you know were the quotes from you're showing your age) Anyway decided to go boat and so far enjoying it, though that may change after tomorrow.

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