Hi again,
You'll be relieved to know that some more progress has been made on this build. Still following the build sequence from the magazine, a lot of the progress has been in preparing skins and parts of components, only to be greeted by the words " Store carefully for future use" at the end of each set of instructions. I have, at the moment, three storage boxes containing parts that have yet to be completed, skinned or painted. This means that, despite all the work, there's not a lot I can put up as finished photographs.
However, as a lot of the issues I'm working from cover skinning, I thought that some modification to the instructions would help get a better result. The problems I've been coming across are the joins where each section of skin butts against the next. This point can be along a stringer (1mm wide) or along a wing spar (2mm approx). This gives very little area to get a secure bond with adhesive and has resulted in gaps in the joins, which will require filling.
My solution was to glue some metal strips (above) across the join areas to act as a more secure base for the skins. This is the port outer wing, with the metal bases applied, and will be skinned in its entirety. Because of this, I've taken some short cuts in painting the interior, leaving it in grey primer. This technique appears to work and gives much better support for the joins. Just not sure if I can get it to work on the sections where I'll have parts cutaway to show interiors
Another problem I'm having is with which adhesive to use. Because the points of contact are so narrow on stringers and ribs, I've been using a strong contact adhesive, Evostik Impact, which gives a good strong bond. The problems with it are that it's very thick, with a tendency to clot and string. This is not a problem when the area is totally skinned but could be a problem where interiors can be seen. I was wondering if anyone could recommend a contact adhesive that's thin (brushable) and doesn't string? Cyanoacrylate (superglue) doesn't work, as it dries too fast (max 20 seconds) for me to cover relatively large areas. I need something that would give at least two minutes application time before drying. Any suggestions would be very welcome.
Next, the wing nosings were added to the port wing, top and bottom and worked well with the new supports underneath but will need some filler. The outer engine frame parts were assembled and test fitted before painting and a metal firewall skin was fitted to the wooden engine support. This is an area very easy to get wrong, as I'll explain next. (The masking tape is protecting the landing lights, as the firewall will be painted in situ).
It's important that that the outer engines are perpendicular to the ground and aren't parallel to the dihedral of the outer wing (see below).
You can see from the illustration that a perpendicular line from the ground, perfectly bisects the outer engine (red line). This is not clear in the magazine's instructions below.
If you were unlucky enough to follow these visual instructions, your placement of the engine would be at an odd angle. This is complicated by the fact that there are no location pins or marks to indicate the correct positioning of the metal firewall to the wooden support and because both surfaces are curved, it is easily mispositioned, as I found at my first attempt.
Instruction 26 is wrong, but easy to be misled by. I've tried to show just how wrong by overlaying the dihedral grid in red. Again, the square mounting frame should be parallel to the horizon line and be bisected by the perpendicular line. Having stuck the metal firewall to the support initially, it just didn't look right so I had to peel it off and start again, this time taking great care to do it properly, which was done with much measuring of angles. Provided that the dihedral of the wing is 5 degrees when attached to the inner wing, it should now be correct.
This is it correctly positioned, and painted, with the engine support cradle added. As this port outer engine will be completely enclosed in the nacelles, I'm just going to do the minimum required of the build. I'll keep super-detailing for the partially exposed starboard engines.
Here is the complete port outer engine skeleton painted and positioned with the oil tank in place. I learnt some valuable lessons mounting this and would change the sequence when assembling the starboard version. I have test fitted the nacelles and so far, everything fits.
Then a test fit of one of the Merlins. There are still parts to be added to the Merlins, particularly the exhausts and the wrap-around coolant tank. However, I know that there are fit problems with both of these when the nacelles are added, with later instructions to remove and cut the coolant tank to fit properly! We'll try and avoid that unnecessary kind of work.
I need to continue this post with a second post, as the original is too long.
To be continued...