How to carve a nose cone, what glue and covering?
|David Cooke 1||08/11/2013 23:48:20|
|48 forum posts|
I'm a newbie and decided that I'm going to be building a 3ch Ben Buckle Super 60 (after given the nod by an old hand). I've built a 21" Micro Super 60 from plan (no kit) and reasonably quite happy with my construction (tissue covered wing).
I've seen some great builds on the web and there is a very nice S60 build dairy on this forum. I am pretty happy with my build skills on everything but the nose cone and covering.
1. It seems that the nose block sections are glued on and then carved+sanded to shape. How do you know what lines to follow on such a shape and how do you get it just so? I'm a perfectionist!
2. I covered a plane many years ago as a kid with iron on Solarfilm (used my mum's iron and gas fire). How do you cover the nose? Again I see some wonderful photos on the web and don't know how to achieve a flawless finish.
3. Year ago I used PVA and that was OK. On my recent build I used aliphactic PVA and was pleased with the "grab". However it didn't really sand well. Is there something better to use? Balsa cement? What's the difference? Also, why epoxy on the thick engine mounts? I'd have thought a PVA joint is stronger than the wood so would suffice?
|Peter Miller||09/11/2013 08:35:18|
10168 forum posts
Glad to see a person who likes real building.
Carving the nose blocks is usually a pretty much eyeball affair but if you want to get it as per the orginal you can make card templates of the plan and side views and carve to them. A good razor plane is a very useful tool.
I use a Zip razor plane which should be available from ten Balsa Cabin. They also supply ythe blades but I buy the old Blue GiIette Blades on Ebay when I can.
Covering compound curves with Solarfilm OR my favourite Solarfilm Supersshrink Polyester, Is a nack. Part of the secret is to strecth the loose par and pull down before ironing down, do this a alittle at a time and you can cover quite a lot of a compound curve.
Covering is an art that needs parctice to obtain perfection. Some poepl can do covering jobs that make the rest of us green with envy. Me included and I mean I turn green wigth envy.
I prefer aliphatic resin, PVA goes rubbery and doesn't sand well, Aliphatic does go had and so does sand better in my opinion.
|Bob Cotsford||09/11/2013 09:47:36|
7972 forum posts
Epoxy on the engine mount to ply formers because the epoxy gives a better bond to hard wood than pva, which relies on penetrating the grain.
To be honest I find any glue leaves some degree of a ridge when sanding as it is harder than the wood. I suppose the answer is good fitting joints with a minimum of glue where it will be sanded.
|David Davis||09/11/2013 10:11:22|
3399 forum posts
I'm also pleased to welcome another builder David!
I have four points you might like to consider.
1. I prefer aliphatic glue to PVA but have been known to use PVA because it's cheap!
2.Covering is a knack which comes with practice but buying a proper iron with an adjustable heat range is a good investment. I use a Prolux myself.
3. Solarfilm offer a DVD on covering. The footage is very old but it teaches you the basic techniques.
4. Consider using Solartex on your Super Sixty. It's available in a wide range of colours and the vintage range offers see-through colours which look a bit like silk or nylon and it's much easier to use than Solarfilm. I use it on most of my built up models with a five foot (1.5 metre) wingspan or greater. My Super Sixty is covered in Vintage Red Solartex.
|Steve Hargreaves - Moderator||09/11/2013 10:17:57|
6720 forum posts
+1 for Solartex.....it really does form around compound curves very nicely & would be suitably "period" on a Super 60...
|6032 forum posts|
|The secret to getting Solarfilm or 'tex to cover difficult curved bits is to have lots of excess to hold onto and pull out as you shrink it down. Just leaving a little does not work well.|
Practice makes perfect...
Solartex is easier to use than 'film especially on curves. Overlaps on Solarfilm can be improved by using Prymol etch primer ( Solarfilm product)
Making nose blocks or canopy shapes is easier if you laminate from several bits....the centre bit being cut to the exact shape to guide you. The outer layers can also be cut to the exact shape at that position.... draw the wood thickness onto the plan then you can see the size of the centre layer, the next layer etc. Sanding to shape is then a matter of knocking off the corners instead of hacking away any old way. Or you could make a thin ply centre and laminate balsa onto each side. The balsa will sand so much easier than ply. The ply will remain as a marker. You could use ply centre in both the vertical and horizontal planes for a better guide. Glider people do this to make a tougher nose block I think.
125 forum posts
Hi David. Great aeroplane the Super 60. Nice and big in the sky especially as the old eyesight fades. As for the nose cone, I doubt if there are 2 home built Super 60s with exactly the same nose shape so whatever shape you arrive at will be modelling perfection.
The solar tex finish has already been described and really is quite straightforward once you have everything set out and to hand. Practice here being the way forward. By the time you have covered the model, you will be an expert.
Epoxy in the engine bay acts both as a very strong glue and a fuel proofer. The engine bearers may be smeared with epoxy and indeed any raw balsa or ply parts too in order to make them strong and fuel proof.
The nose cone should of course be planed, shaped, and sanded in your living room to achieve the highest standard. I really do wish you all the very best.
Edited By Gazza58 on 09/11/2013 15:01:42
|David Cooke 1||09/11/2013 15:30:15|
|48 forum posts|
Thanks for the replies chaps.
Epoxy on ply formers now makes sense - obvious now you said it Bob
I'll look up Solartex - I'm of course some time off needing to cover! I can make some dummy parts, ie wing tips to practice.
How do you cover the vertical fin? Especially the front most section as it tapers off the fuseulage. Would seem easier to cover prior to gluing to the fuselage?
Weather permitting I'm going to a vintage event tomorrow at Aldershot RC's flying site so hope to see some Supers there. Camera at the ready and interogate their builders.
|Nigel Day||09/11/2013 17:07:07|
1158 forum posts
I'm in the process of the same build. Just getting to the covering stage and moulding the nose cone too. I have the same question about covering the fine before or after attaching it to the tailplane.
The split elevator has me thinking too. I've got three of the older, established 'reference' titles' with different ideas. I'm inclined to go with a split connection from a pushrod coming our either side of the rear fuselage to a control horn on each part of the elevator. Course, I'm a control horn and wire rod short in the kit though but that can be fixed with a quick visit to my local model shop.
|David Davis||09/11/2013 17:36:02|
3399 forum posts
I covered the fin and strake first and reinforced the joint by using triangular stock in the angle between the fin and the fuselage top.
|Nigel Day||11/11/2013 17:37:37|
1158 forum posts
Yes, I'd thought that the tailfin should be strengthened like that so I've covered the fin and will cover the tailplane with the fin in place, overlapping the solarfilm at the base of the fin. I'm going to do the same with the skid at the bottom.
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