A solid model elements Miles Gemini

[Balsabasher]

This model is not a true solid but has so many blocks to carve it comes under the 'Solid model elements' category the plan is a 'Model Aircraft' drawing circa fifties I think,well it has been in my collection now for years and one day I said it would be built,and so last week I cut all of the parts out for the Miles Gemini,it is a control line subject but seeing as I have no small diesel engines any more I doubt whether it will be used as such ? just the challenge of making quite a fiddly model from yesteryear is enough of a draw for me,here it is being assembled today,lots of good old carving to do and planking the fuselage top and bottom.
Barry.

[lastvautour]

It looks to be  a fair size. I have a Cessna 170 still pined to the board and like you, someday I will get back to it.

Lou

[Balsabasher]

Wingspan 36 inches,length is 22 inches,a deep draw canopy moulding is required which is going to be a challenge Lou.
Barry.

[Balsabasher]

A bit of progress on the Miles Gemini,the wings have been built and attached,the engine nacelles need building up and the lower surfaces sheeted as well plus the wingtips need carving up.
Barry

[Balsabasher]

The Miles Gemini is coming along with the chunky balsa blocks being shaped up and added as can be seen here,lots of solids in one !
Lots more pictures to look at in the new gallery entries
Barry.

[Balsabasher]

An update on the Gemini,the undercarriage was added today plus the tailwheel,the sealing and finishing starts now.
Barry.

Shown with others from the Miles stable,another Gemini,a Messenger and a Whitney Straight.

[dave_t]

The three painted models in that photo are absolute gems. I am sure the Gemini will finish up nicely too. Hmmm, I need to get back in the workshop this week.

[Balsabasher]

Yes three newly painted shiny solids Dave,I forgot to say to Lou that you can add the bronze Miles Gemini G-ALZG and the Whitney Straight G-AEUJ to this years model list.
I am trying out a new finishing technique for the larger Gemini giving it several thin coats of thinned PVA adhesive,this serves to strengthen the balsa grain and raise the grain at the same time the first time around,having used this idea before I know it works well.
Barry.

[Will]

I am trying out a new finishing technique for the larger Gemini giving it several thin coats of thinned PVA adhesive,this serves to strengthen the balsa grain and raise the grain at the same time the first time around,having used this idea before I know it works well.
Barry.

Barry, does thinned PVA harden the balsa as well as cellulose based sanding sealer?  I assume it would take longer to "go off" before you can sand, being water-based but that might be worth it to avoid cellulose smells and significantly cheaper too, as cellulose thinners seems only available in model shops - even auto-parts shops don't seem to carry it round here.
Will

[Balsabasher]

Will I have made an interesting discovery,it seems that the waterproof variety of PVA adhesive dries much better for sanding than its non waterproof counterpart,so far I have applied three very thin ( consistency of milk ) coats of this home made sealer and the finish is looking really good after a bit of a rub down in between coats,yes no smell and providing that you are prepared to wait longer for it to dry then it is a first class alternative to cellulose based materials,the next experiment is to incorporate some talc into the thinned solution,I do not see why it should not do the same as conventional sanding sealer ? but it seems that you do not really need any fillers added because after three thin coats it dries out to a smooth even finish.
There is one big advantage in using PVA as a sealer,it knits the grain of balsa together and really toughens it up as well,initial coat will fuzz up the finish ready for that all important first sanding session.
I have used this system many times before but with earlier PVA's today they are vastly improved products with finer polyvinyl beads for starters giving a much more creamy adhesive,economy wise it lasts well,what I have been doing is dredging out the heavy stuff in the bottom of old containers in the workshop,use a bit of warm water,not hot but just tepid,use a jam jar or similar and give it a shake,allow to settle and use one of those stiff artists brushes for the first coat gradually using a softer bristle for the latter coats and just wait to see the smooth finins appear ! it takes a bit more patience than conventional cellulose finishes but you get good results.
True formulae cellulose thinners is getting difficult to obtain these days,most commercial shelf thinners now do not mix with some cellulose paints,they just curdle them,I found this out trying to clean a batch of brushes,I got lazy and fed up of spending money on thinners and  brought some ordinary acetone to soften them as a batch job,commercial grade dope remover is basically just acetone,the fumes are deadly so watch them and avoid use indoors.
PVA finishes take rattle can spray paints no bother,there is no reaction as far as I have seen,I am going to use more PVA for sealing with the added hardening it gives to the wood,especially balsa,the flying model lads use it to taughten tissue as well,it is slightly heavier than clear dope but not much especially if you really thin it out,two coats on tissue should be enough and it will not warp as bad as dope but still pin surfaces down using tiny wedges to keep clear of the building board.
Another trick is to mix PVA with micro balloons,you can make all sorts of consistency of fillers this way,you can get bags of micro balloons from most good model shops.
The trick is to experiment,try different things,even flour and water paste was used as a substiture during WW2,so why not flour mixed with PVA ?
Barry.