Model Boat Mayhem

Mess Deck: General Section => Beginners start here...! => Topic started by: Philrees on January 09, 2021, 06:28:37 pm

Title: First time builder - Mantua Mincio planking
Post by: Philrees on January 09, 2021, 06:28:37 pm

I’m new to boat building so any help I can get will be gratefully received.
The planking on the boat is balsa strip, covered with tissue paper glued on with 50/50 pva and then very thin mahogany veneer.
My questions are a) can I seal the tissue with cellulose aircraft dope before applying the mahogany and b) what glue would I use to apply the mahogany.   C) recommended varnish for the mahogany and d) will the cellulose dope help make the craft waterproof?
Thanks in anticipation.

Title: Re: First time builder - Mantua Mincio planking
Post by: RST on January 09, 2021, 06:38:02 pm

Just before going any further I might not be the only person who wonders why the tissue paper layer before the second mahogany?  Might also wonder why the tissue paper might be layed on with diluted PVA rather than the more regular products but each to their own and more than one way to skin a cat.

Title: Re: First time builder - Mantua Mincio planking
Post by: radiojoe on January 09, 2021, 06:46:38 pm

I've used this tissue/pva method many years ago it's amazing how much it stiffens balsa. but if it were me I wouldn't use the cellulose dope the fumes last a long time even when dry and may cause problems with the second layer, Aliphtic wood glue for the veneer just my thoughts.


Joe.

Title: Re: First time builder - Mantua Mincio planking
Post by: Philrees on January 09, 2021, 08:18:50 pm

Thank you both for your replies.
The tissue paper came with the kit and the instructions say to use diluted pva.
So am I right in thinking that all the waterproofing will come from the varnish on the mahogany and can you recommend a varnish to use?
Many thanks.

Title: Re: First time builder - Mantua Mincio planking
Post by: chas on January 10, 2021, 09:34:08 am

Hi Phil, I wouldn't use dope in this situation either, too much risk of the fumes hanging around and damaging the varnish. Use the dilute pva and tissue, it stabilises the balsa then apply the veneer with aliphatic glue. For the varnish, I suggest you pop in to Barnett's ( I used to live in York) and ask for marine varnish, they will also advise on how to dilute it for the first coat or two.
Charles

Title: Re: First time builder - Mantua Mincio planking
Post by: Philrees on January 10, 2021, 11:46:19 am

Hi Charles
Greetings from York.

Thanks for your advice.  Barnitts is one of my favourite shops but, unfortunately, it’s out of bounds at the moment as we’re trying very hard to follow lockdown advice.  So it looks like an online buy.
Best wishes
Phil