Model Boat Mayhem

Dry Dock / Shipyard: Builds & Questions => Springer Tugs => Topic started by: ck_ni on August 13, 2019, 02:57:24 PM

Title: Balsa vs Ply
Post by: ck_ni on August 13, 2019, 02:57:24 PM
When it comes to building a springer, is it better to use 6mm balsa or 6mm ply for the hull sides? or does it make a whole lot of difference.


And if 6mm ply for the sides and say 2mm ply for the bottom, is the 2mm ply suitable to make the wheel house etc from or should it be made from something else?


Ta,
Chris
Title: Re: Balsa vs Ply
Post by: chas on August 13, 2019, 03:26:16 PM
I love balsa for modeling, but in my opinion it has no place in a springer. They always need ballast or SLA batteries so using 4  or maybe 6 mm ply for the hull is fine, And I used 1.5 mm for the bottom because I had some and it's easier to bend than thicker stuff. Most springers have a hard bumpy life so balsa wouldn't be up to the job.
    Because they aren't particularly stable anything above deck is best built light but strong, 1 mm ply or plasticard is fine maybe with balsa stretchers or bracing if your design needs it.
   The plans for the official formula to make a standard springer are online, and the Buxton model boat club has an excellent section on them.
  Chas

Title: Re: Balsa vs Ply
Post by: ck_ni on August 13, 2019, 03:29:51 PM
Thanks for the reply, I have used balsa before for modeling, mostly in planes and figured it was a bit light for a springer but I have seen a few built from it and that what made me question.


I will go with some 6mm ply... good to know the 1.5mm ply was easier to bend than the 2mm.


Ta,
Chris
Title: Re: Balsa vs Ply
Post by: john44 on August 13, 2019, 05:41:52 PM
I agree with chas, balsa would not be strong enough for the springer style of boat.


John
Title: Re: Balsa vs Ply
Post by: JimG on August 13, 2019, 05:51:15 PM
Unless you are going in for Springer Combat sessions there should be no reason why balsa cannot be used. You may need some thicker sections but there is enough room inside that loseing some through thicker hull sides will not matter. If you are worried about damage to the outside surfaces  then skin it with epoxy glass fibre, a couple of coats of lightweigh glass cloth will make it near bulletproof. If really worried then carbon or kevlar cloth is available. %%
Jim
Title: Re: Balsa vs Ply
Post by: john44 on August 13, 2019, 07:02:50 PM
The cost of balsa, glass cloth resin all that rubbing down, I,d get a hull from models by design.
Just another option.

John
Title: Re: Balsa vs Ply
Post by: ck_ni on August 15, 2019, 11:39:02 AM
Thanks for the replies everyone.
I definitely want to build my springer from scratch so a kit isn't something I am interested in... maybe if I decide to build something bigger or more complex.


Another quick question, I have sorted some 6mm ply for the sides and other pieces, I also have some inch square and 2x1 inch soft wood I can use for other areas as well as some thinner pieces.


For the bottom of the boat, I know most folk recommend 1.5mm or 2mm ply... I had a check round my local stores here in Northern Ireland and I cant find anything in stock.


I can get 2mm Balsa or .8mm ply.


I can also get lots of thickness of plasticard, would and is it acceptable to use this for the bottom of the hull? and if so what if the best way to stick in to the wood... wood glue, superglue or epoxy.


Apologies if these are silly questions.
Ta,
Chris
Title: Re: Balsa vs Ply
Post by: john44 on August 15, 2019, 12:39:42 PM
Chris The only silly questions are the ones you don't ask.
With the thickneses of the wood you are using I favour fast setting wood glue.
For the base use either the wood glue ( water proof type) or resin.
You can always double up your .8mm for the bottom.
What I normally do is use 15 min resin and staple the bottom and deck down
The staples are easy to remove and holes filled before painting etc.
It just saves time trying to clamp the parts.


Hope this helps
John
Title: Re: Balsa vs Ply
Post by: SailorGreg on August 15, 2019, 07:23:36 PM
As has been mentioned before, build it heavy, or you will be deparately trying to shoehorn lead into the hull to get it somewhere near its waterline. I built my Springer out of stuff I had to hand, so it has 6 mm ply sides, 10 or 12 mm bow and stern pieces, and a balsa planked bottom, because that's what I had. (The balsa strips are laid across the hull, so no problem with following the curves, and I put a layer of glass and epoxy over it to stiffen it up and protect the hull when I put it down on hard surfaces.)

One thing I found was to ballast the hull so that it sits bows up when stationary.  Then when you get going it levels out but doesn't try and become a submarine.

Good luck, and enjoy your build.

Greg