<-- 1/48 Mosquito PR.IX -Twin Engined Aircraft WWII

[Airframes]

No bl**dy plastic kit is going to beat me Wayne - it either gets sorted, or hammered !

Got the port wing root gap filled, and both of those cowling gaps done, along with the panel lines along the center of the upper cowlings, which I feel sure shouldn't be there. The starboard wing will be fitted (I hope !) after the filler in the cowling gap has set and been sanded, and I'll post pics shortly.
For Robert's benefit, I'll include a short series of pics illustrating the method of applying and smoothing the 'Milliput', prior to sanding and final finish.
Back soon .............

 

[Robert Porter]

Thank you in advance! Those gaps looked worse than anything I have yet encountered so it would be educational to see how you deal with them!

 

[Airframes]

Well Robert, here's how it's done.

First, that gap at the leading edge of the port wing root was filled with stretched sprue, slightly wider in diameter than the gap. This was cemented into the gap, and then repeated applications of liquid cement were brushed over the sprue, to soften it, and it was then pressed down into the gap, smoothed off using the flat of an old scalpel blade, and allowed to set.
Once fully set, it was lightly sanded, finishing off with worn 1200 grit wet and dry, used dry. Once primer has been applied, any imperfections can then be sanded out and, if required, filled with a mix of clear gloss enamel varnish and talc.
The larger of the two cowling gaps, on the starboard wing, was going to be filled with plastic strip. However, after testing this, I decided that a better option was to use 'Milliput', and therefore both cowling were filled with the putty, as described below.

PIC 1. The wing root gap after filling with 'melted' stretched sprue, and light sanding.
PIC 2. The larger of the two cowling gaps (2 mm wide and around .75 to 1mm deep), and the unwanted panel lines, filled with 'Milliput' and awaiting sanding.
The sequence of pics below describe the process so far.
PICS 3 and 4. After mixing and kneading the 'Milliput' for at least three minutes, in order to ensure the catalyst is fully absorbed, thin 'snakes' of the mixed putty were rolled on the cutting mat, ensuring the surface was clean, and free from dust or other debris. These were then lightly pressed into the gap and panel lines, and then pressed down using the flat of an old scalpel blade, retained specially for this purpose. This is a cheap 'clone' of the X-Acto type, and is used to cut the putty, and to act as a spatula when applying to the surface to be filled. The blade is cleaned regularly, as any imperfections will be transferred to the putty being applied.
PIC 5. With the putty now adhering to the gap / panel line, it is pressed down firmly, but gently, and smoothed off, both actions being done with a wet finger tip. For final smoothing, the flat of the scalpel blade can be 'dragged' across the surface, again doing this with the blade, and the putty, in a wet state.
PIC 6. Once the moisture has evaporated, or been dried by wiping over with a dry finger, the excess putty can then be lightly shaved off. Any thin smears left on the overall surface can be removed by very lightly scraping.
Although it helps to get the surface as smooth as possible, the aim is to leave the surface of the putty slightly 'proud' of the surface of the plastic. It's much easier to sand back, than to have to add more putty if the dried 'Milliput' has set below the surface edges being filled !
PIC 7. Once shaved, the putty is again smoothed with a wet finger tip, and then allowed to set for at least 12 to 24 hours.
PIC 8. This is the narrower gap on the port cowling panel, filled, and being smoothed off wet. The panel line along the length of the cowling shouldn't be there, so this was also filled at this time, using a wet 'slurry' of the putty, wiped across the panel line, and allowed to flow and set. Once set and sanded, any imperfections in the panel lines can be treated with the varnish and talc method.
PIC 9. After treating the panel line mentioned above, some erosion of the putty in the main gap was noticed, so another thin 'snake' of putty was applied, and pressed down and smoothed off as previously described.
PIC 10. The gap and panel lines filled, and being allowed to set. Finishing will be done, after at least 12 to 24 hours (see below), by shaving, scraping, sanding and final polish, which will be described and illustrated in the next progress post.
Note the 'left over' lump of mixed 'Milliput' - don't discard this, as it's a good indicator of the setting / curing process. If the relatively large lump has set hard, probably after around 12 hours, possibly more, then it's virtually certain that the filled areas will have set also. The 'lump' can be tested periodically, by gently and lightly pressing the tip of a scalpel blade, or needle, into the putty. After around four hours, there will be some resistance, but the putty can be penetrated. When it's possible to only just make an impression, by pressing the pin or blade tip with a little more pressure, and also be able to scrape or shave the putty without cracking or crumbling, then it's probably set. A final test is to cut a thin slice off the end of the 'lump', and do similar tests on the inner core, which should set before the outer 'skin'.
After two or three days, although the actual curing will be complete, the putty should be virtually rock hard, but able to be worked as required.
Once the surface of the putty has been sealed by primer and / or paint and finishing coats, it will be very tough, and will survive even if the model is pulverized with a lump hammer !

I hope this is helpful, and I'll be back some time tomorrow, when the puttied gaps have fully hardened, to show how the dried putty is finished off to give a smooth, even and flush surface.

 

[Wurger]

 

[T Bolt]

What a struggle you've got going there Terry! At least the glue seems to be sticking to the plastic unlike a certain Buccaneer from Airfix I remember from a few years back...........

 

[Crimea_River]

Looks like you're well on your way to taming the beast Terry, and great tutorial.

 

[Robert Porter]

Awesome info! Thank you, it was very clear and well illustrated. I am positive it will help in my efforts!

 

[turbo]

Thanks for the tute Terry

Once the surface of the putty has been sealed by primer and / or paint and finishing coats, it will be very tough, and will survive even if the model is pulverized with a lump hammer !

which it sounds like it will be...

 

[Gnomey]

Looks great so far Terry!

 

[Robert Porter]

I have decided my first failed project, my B-17G, will become my test bed for filling seams, paints etc. Although I strongly debated the lump hammer approach above!

 

[rochie]

What a struggle you've got going there Terry! At least the glue seems to be sticking to the plastic unlike a certain Buccaneer from Airfix I remember from a few years back...........

Glenn, every time I visit Terry I see that Buccaneer all painted up minus it's outer wings looking pretty good for all the trouble Dogsbody had building it

Looks good Terry

 

[Airframes]

Thanks very much indeed chaps.
But Glenn, you had to go and mention that Bucking F***ingneer !!

One of these days, I might finish the Bucker !!

 

[Crimea_River]

...or it might finish you.

 

[Robert Porter]

Turn it into a diorama of a wreck, you can take out some frustration and the process of wrecking it is so satisfying and covers a plethora of sins!

 

[Airframes]

Nah, I just need the time and motivation to get it out of the cabinet (which I can't get to at the moment, as there's stuff piled in front!), stick the wings and stores on, and finish the final details.

Anyway, one cowling is now done, and the smaller gap in the port cowling is currently being worked on.
So, to continue with illustrating the process, the pics show the stages up to 'proofing' with a thin coat of paint.
Before any work commenced, the left-over lump of 'Milliput' was tested for hardness, and found to be as solid as a APDS shell, which confirmed that the filled areas would be fully set and hardened.

PIC 1. Before any sanding is done, the 'Milliput' is first lightly shaved, stating at the cowling joint, and using a very light touch with the edge of the scalpel blade, to first create the demarcation, and then shave-down the inevitable high spot where the putty was smoothed over the curve to the horizontal joint. Note the 'Milliput' dust, indicating just how delicate the shaving has been.
PIC 2. The top and sides are now shaved, moving the blade in one direction only, indicated by the red arrows, and keeping the edge of the blade parallel with the surface at all times, at an angle of approximately 45 degrees from the vertical.
PIC 3. This process is now repeated across the cowling, again in one direction only, shown by the red arrow, and again very lightly and gently.
PIC 4. The putty is then lightly sanded, using a medium grit wet and dry paper, used dry, before finishing with a worn, 1200 grit, used first dry, and then wet. This gives the final smooth, polished finish to the putty, and also removes any scratch marks in the plastic from previous sanding.
The surface is inspected regularly during the sanding process, both visually, against a back light, and by doing the 'finger nail test'.
Close inspection here revealed a very small depression, indicated by the pencilled arrow at bottom right. The other two arrows show a couple of rather spurious panel lines, which were then filled with CA adhesive, as was the small depression, and sanded down before the glue had time to fully harden. There is also a very small 'bump' near the front edge of the cowling joint, which is the remains of a sprue attachment point, and this will be removed later.
PIC 5. The finished job, ready to be checked by a coat of paint.
PIC 6. A thin coat of dark grey enamel was roughly applied, by brush, in order to check the surface for defects. Apart from the filled joint showing through the very thin, almost transparent paint, as a lighter line, the surface is smooth and even, and the filled gap should not show once the model is primed and painted.
The dark grey paint will be sanded back before the primer is sprayed, and there are two small vents and an access panel to add to the upper cowling, not included in the kit, and these will be fabricated and engraved respectively.

If I'm able to get the port cowling done later tonight, I hope to get the starboard wing fitted and, with luck, also fit the tail planes, then prepare the model for masking and the first primer coat.

 

[rochie]

Nicely done Dogsbody, something I need to start to do, making more of an effort on seams and gaps

 

[Wurger]

 

[Airframes]

Thanks Karl and Wojtek.
I'll admit, when I first saw the size of the gap on the starboard cowling, I though "Oh,s*it !"
Just hope the smaller gap on the other cowling turns out as well.

 

[T Bolt]

Thanks very much indeed chaps.
But Glenn, you had to go and mention that Bucking F***ingneer !!

One of these days, I might finish the Bucker !!

Finish it and I won't mention it again!
I should talk, every time I sit at my bench I lookup to see a gear-less Stirling staring back at me along with a Fw190D, P-40K and F-102

 

[vikingBerserker]

Nice work!