1/18 Curtiss P40C

[airscale]

hello everyone

 

No way of dressing it up, but I have changed subject again...

 

I will go back to the Fairey Firefly - this is it's second time of falling out of favour, but when you get the urge what do you do?

 

My new flame is the early longnose P40. I have always thought it would make a good subject for me and very nearly started one after my P51, but didn't fancy another American aircraft in quick succession.

 

It's easy to see why..

 

 

..beautiful lines, natural metal and technically interesting.

 

This is G-CIIO operated by The Fighter Collection who have said I can come and take at look at her once we are into the New Year and assuming there is no covid funny business preventing a visit...

 

I have spent the last month or so researching and finding out about the airframe and the differences with the later short nose P40s and the earlier P36 - of which there are many. I also liked the timing with the GWH 1/32 kit coming out as folks will be talking P40's for a bit

 

I had Jumpeii Temmas plans scaled and corresponded with Witold Jaworski who has digitally modelled the P40C and had done loads of research and analysis of factory drawings

 

One thing I really looked forward to was doing what I did with my P51 and getting stuck into those drawings to replicate everything part by part. This was always something that hindered the Firefly, I just don't like working in a vacuum, I like the research and knowing what I am making is accurate

 

An example like this - here is the tailwheel door in the parts manual..

 

 

..I can find the part number and in Aircorps Library, look up the drawings..

 

 

..then scale and copy the drawings to make up a set of photo-etch parts..

 

 

..I did this hundereds of times and now have the mother of all PE sheets at 28cm by 47cm with everything I thought I could do in PE represented..

 

 

 

i thought I would base the model on the 21st Century Toys 'model' as I did with their Fw190D -this was on the basis that while it is a toy, the 190 was dimensionally pretty accurate..

So a trip to ebay and £160 lighter, one turned up..

 

Once the 'model' arrived I set about destroying it into it's component parts - this involved sawing some of the nose elements in half so I ended up with effectively two fuselage halves..

 

cue the first plan comparison and a very deflated feeling...

 

 

..it's too short, too narrow, has what looks like the late chin profile and is generally all over the place..

 

..the rear fuselage is particularly out..

 

 

..now, I did toy with the idea of just getting on with reworking it, but the more I looked, the more work I found - in the end I was trying to justify it because I had spent the money..

 

In the end, I bit the bullet and decided to scratch build it - I have no excuse - I have great drawings and having just scratchbuilt a Hawker Fury so feeling pretty confident..

 

..first step was to get a sheet of perspex acrylic to trace out a 'keel'...

 

 

..I used a scalpel to score the perspex - you may juts be able to see some of the station lines here (on the red line)..

 

 

..once I had all the station points and outlines done, I used a jigsaw and a cutting disc to cut out the profile - with a big bit missing for where the cockpit is..

 

 

..this again told me how out of whack the 21st Century Toys model is..

 

 

..using Jumpeii's profiles I cut out all the fuselage station formers..

 

 

..and cemented them in place using a mini set square..

 

 

 

..then I soldered some square brass stock to get the dihedral right for wings to slide into - there is a little perspex jig holding it upright inbetween them..

 

 

..they were epoxied in place with the smaller sliding box sections in place so the angles and dangles can be seen and the positioning made correct..

 

 

 

..so there we are - thousands of hours of work to go, but it feels good to have something fresh on the bench and thats what it's all about right?

 

TTFN

Peter

[John_W]

Oh my goodness. 

(Pulls up a chair)

[Jonners]

Wow.

Another beauty on its way, and another tutorial in master modelling to enjoy. That's already clearly a huge amount of work carried out, Peter, not to mention the frustration of the expense of the less-than-accurate C21 model. Your commitment is as admirable as your skill! I'm looking forward to watching this take shape...and being thoroughly impressed in the process.

Jon

 

[k5054nz]

As I've posted elsewhere, while I much prefer the P-40E and later variants I am very, very excited to see you start this build Peter. And with such a great initial post (21st Century Letdown aside)!

[Lewis95]

I sense there is much to learn here.... Will you be 3D printing parts for this bird?

[JTninja]

Wow, intense start

[Gondor44]

Another airscale build..... I'm in

 

Gondor

[airscale]

hey everyone

 

On 12/30/2021 at 1:47 AM, Lewis95 said:

I sense there is much to learn here.... Will you be 3D printing parts for this bird?

 

 

Hi Lewis - yes, the spinner & wheels at least will be 3D printed, once I have designed them that is!

 

I have been going mad on the PE design to date and now have two monster sheets after I decided to include the flap innards..

 

 

 

 

..the first thing to set about was the nose - it's all very well having a solid perspex keel and solid formers, but there is a bit of work to do to open it all out for the chin intake and exhaust area..

 

I mocked up the PE radiator front so I could orient what needed to be done and set about grinding and cutting out the lower chin area..

 

 

..also the rear where the cowl flaps will go..

 

 

..added two ali plates that will give strength to this bifurcated area..

 

..you can also see the ali tube I let into the upper nose for the basis of the (carb?) air intake

 

 

..the inside of the cowl is lined with sheets that duct the air from the intake to the 3 round prestone radiators - I have no drawings of this area so all I know is the shape of each intake segment, and the round radiator diameter at the end of it. to form the shapes, I needed to make bucks on which to form the metal sheet intakes. I started by laying out blanks of the shapes at each end and building a simple frame that held them in the right position

 

Once the frame was removed from the model, a pole was added to lock that position and the frame cut away, resulting in these funny shapes..

 

 

..those shapes were then built out with scrap plastic & balsa and filled with P38 filler and ultimately refined into the bucks needed..

 

intake shapes at the front..

 

 

..radiator shapes at the back..

 

 

..then annealed litho can be formed on the bucks to form the trunking..

 

 

..these were then primed and painted as I won't be able to get to them once fitted..

 

 

..then a bit of jiggling and they are fitted..

 

 

..I slathered a bit of epoxy around them to help them keep their shape..

 

 

..and the process worked - I also added a tape ring where they meet the rads which is like a canvas boot but you can't really see it..

 

 

..the transition is quite smooth..

 

 

..and thats it for now, rear area next..

 

 

 

 

TTFN

Peter

[k5054nz]

Peter, on another forum someone used the word "joyful" to describe watching your builds and I agree, that's the word I've been searching for. It's also wonderful to see how quickly (famous last words!) the P-40 is coming together.

Edited January 3, 2022 by k5054nz

[72modeler]

I am speechless!

Mike

[Biggles87]

Me too!

 

John

[Pastor Rich]

Peter,

 

I had an informed feeling that you had veered off the Firefly again for something in polished metal.  My search last night was rewarded with finding you here!  Thank you again for sharing your inspiration and model building prowess.  Are you doing a Patreon page for this or just sticking with BM?

 

Happy New Year, 2022!

 

PR

[wellsprop]

Oh yes...!

 

Ready to watch the magic happen

[airscale]

Hi all, thanks for your kind comments

 

On 1/3/2022 at 1:33 PM, Pastor Rich said:

Peter,

 

I had an informed feeling that you had veered off the Firefly again for something in polished metal.  My search last night was rewarded with finding you here!  Thank you again for sharing your inspiration and model building prowess.  Are you doing a Patreon page for this or just sticking with BM?

 

Happy New Year, 2022!

 

PR

 

Hi PR - no, no patreon for me anymore - I found making videos took quite a lot of time and changed how I approached modelling, so regretfully I killed it off

 

 

So, not back at work yet after a long Xmas break so got some good benchtime in

 

I found I had made the chin intake to plans that were incorrect - you can see the 'dividers' are in the wrong position

 

 

so a days work was ripped out, and another days work put into doing it all again - the lesson here is always check references!

 

 

 

Wanted to get the rear of the chin intake sorted - a few things to note..

 

see the big natural metal duct that takes the air out of the upper two radiators to the exit

 

 

..and the rads themselves are mounted in a bulkhead behind the lower ring former that holds the cowl flaps.. you can also see the ducting here with holes in for the cowl flap control rods..

 

 

..I started by nicking one of Mrs airscales mascaras as it was the right diameter to give me good forms to start making a mould to form the duct over - she put up a small fight, but with a promise to buy her a better one, it was soon cut to bits..

 

I made up a plastic card 'bath', put the sectioned mascara tubes in it and filled it with P38 filler - that gave me a good basis to make the mould which I later pulled a vacform over..

 

 

..as the real one is natural metal, I needed to skin this part, so while it was still on the mould I started working some annealed litho..

 

..the main tools of the trade here are a tiny ball pein hammer and a coffee stick..

 

 

..after working it, sanding it and wire wooling it, the part was getting near to being finished..

 

 

..the three components - it took me way longer to make the mould bits than the part itself..

 

 

..added the holes and rivets that hold this panel..

 

 

 

..to actually integrate it into the airframe I had to section the keel and remove a section so I could fettle it and get it in position..

 

..also started on the bulkhead..

 

 

..added a black plastic card backing to the bulkhead and cemented it all in place.. the radiators themselves and some of the fittings are in the monster PE set I have coming from PPD next week

 

 

 

 

..it was quite a job to get all this to line up - especially the angles and sit of where the duct meets the rads..

 

 

..next up, I am going to try filling the fuselage with this sculpting foam and then a skin of P38 before skinning the airframe in metal..

 

 

 

..should be interesting - hope it works out

 

TTFN

Peter

[Pastor Rich]

I totally understand your feelings on Patreon as it struck me as taking a lot of wind out of your sails making content and having to constantly make content.  (A different and perhaps distracting creative endeavour unto itself).  No worries.  MOJO all the way!!!

 

Filling with foam is a little different for you.  The F7F was not filled although I recall you filled part of the Spit did you not with a two-part liquid foam?  (Or was it the Ta 152?  Don't quote me...)  I am revisiting my 1:10 CT-114 and am planning for a balsa build-up with formers and stringers over a keel then plastic card covering that.  Not too unlike your Firecat...which by the way I absolutely LOVE!!!

 

If you ever had a taste for Lightnings, the F-5 family was well known as being stripped down to bare metal.  Who knows?  Your Tomahawk could pave the way for making a twin Allison project!  But should such a bug visit your taste buds I would be happy to help with research as the F-5 and Lockheed Lightnings are my thing.  Come by my place come time at www.34thprs.org. 

 

Cheers!

Edited January 5, 2022 by Pastor Rich
To err is human but forgive is Divine.

[airscale]

Thanks PR & afternoon all

 

I started out by trying this new sculpting foam material - there is a keel assembly that is underneath the P40 made of 3 or 4 sections, so I got the drawings and scaled a floor and three cross sections. From here I filled the blanks with foam and sanded it down.

 

I found a saw works best for main cuts, then a rasp for major shaping and then a sanding stick for finessing. One thing is it makes a lot of gritty dust which gets everywhere - it is hard stuff a bit like the stuff flower arrangers use

 

 

I used quite thick card in my dental vacformer to pull a couple of copies of keel parts - found they make for a great way to knock up moulds for these sorts of parts which previously I would have spent longer using P38 filler. It sands really easily and stuff like this can be made in minutes..

 

 

..In thinking about using it on the airframe itself - I wanted to be happy I could skin metal onto it so made up a test piece of foam with compound curves

 

..the first try just using it raw failed - the contact adhesive largely absorbed into the foam and the surface area of all the structure between what are essentially foam bubbles is not enough to get any adhesion

 

I tried a skin of P38 filler & primer like I would anyway and this fixed the adhesion - but care is needed in forming the sheets as its quite easy to scar the foam even with hard wood coffee stirrers

 

when i riveted the skin once its in place (which has to be done for compound curved areas), the distortion of the metal is more pronounced and there is a danger of going straight through it and puncturing the skin

 

a tried a wash with thin CA and that helped a little with rigidity so I am sure with a combo of filler and CA I can make it work..

 

with the test done it was time to start doing the airframe.. the pro's in being able to get a 'body' in a couple of hours vs being careful with skinning is too strong - as opposed to days of trying to plank or fill all the areas with balsa & P38..

 

 

..soon the airframe was done and the basic shaping complete - I will probably vacform the chin area and the area under the spinner will be P38 as there is a lot of scalloping and compound curves..

 

 

 

 

 

..the keel parts sit here..

 

 

 

 

..so now I need to give it a skim of P38 and do A LOT of refinement before its in a fit state to be skinned in metal later..

 

TTFN

Peter

[CJP]

Hello Airscale,  always interesting to watch your builds come together - this method with formers & foam looks very strong & neat - I'm a bit disappointed to hear the Firefly is parked again

CJP

[cati]

Hi peter

 

Great work as always . Noticed on lsp and now  here discussion on toughening up foam. I build Rc planes and used to use Epoxy with foam . I recently tried some of deluxe materials products and been impressed foam armour and eze coat. The company is very helpful and worth chatting to

 

https://deluxematerials.co.uk/collections/r-c-modelling/products/foam-armour

[DJJunis]

Absolutely incredible skills Peter. Thank you so very much for sharing.

 

All the Best!

Don

[k5054nz]

On 1/6/2022 at 5:46 AM, airscale said:

hope it works out

in my humble opinion I think it will! Fantastic work thus far Peter, informative and inspirational to boot.

[Pastor Rich]

Peter,

 

Your detailed notes on adhesive absorption and delicate nature of the foam to accept distortion from surface detailing is MOST appreciated.  Pin points that are well taken!  I have been mentally working through how to build the airframe of the CT-114 and am planning on a hardwood keel with balsa formers, stringers and possibly sheeting as the build up.  Panels would be cut/formed plastic sheeting.  Raised rivet detail to be impressions from the back side of the skins pressed against a balsa backing.  I'm very comfortable working in wood so my natural choice.

 

Thank you again  for sharing your artistry!  MOJO be here!!

 

PR

[Sabrejet]

Another gem in the making: your work is inspirational!

[airscale]

evening all, thanks for stopping by

 

On 1/7/2022 at 9:43 PM, CJP said:

Hello Airscale,  always interesting to watch your builds come together - this method with formers & foam looks very strong & neat - I'm a bit disappointed to hear the Firefly is parked again

CJP

 

Hi CJP - thanks - yes shame about the Firefly, but I will go back to it, so thsi is just an interlude

 

 

 

On 1/7/2022 at 10:26 PM, cati said:

Hi peter

 

Great work as always . Noticed on lsp and now  here discussion on toughening up foam. I build Rc planes and used to use Epoxy with foam . I recently tried some of deluxe materials products and been impressed foam armour and eze coat. The company is very helpful and worth chatting to

 

https://deluxematerials.co.uk/collections/r-c-modelling/products/foam-armour

 

 

Thanks Cati - appreciated - will check them out, though - I did some experiments with Z-Poxy resin both with and without tights and not sure it's for me..

 

 

..the findings were mixed - just adding a layer to the foam gave a bit of a skin (on the right), but I could still easily deform it with a fingernail... with the tights, the surface was way stronger but very textured so would need a lot of work, or perhaps more coats..

 

In the end, I decided to stick with plan A and skim the foam and fuselage with P38 filler..the skin is very thin and ultimately still quite fragile, but with a mix of CA and filler it's good enough to form and rivet litho over..

 

 

..it took a bit of work, and where I sanded through the filler to the foam,  I just washed it in thin CA and skimmed over it again..

 

 

 

..then I added a cotton datum and chopped out big holes to add boxes for the exhaust areas - these wil ultimately be 3D printed so all I need is the 'hollow' that goes behind the skin panel..

 

 

..then the fuselage was refined, the lower cowl vacformed (& here only taped on) and the body shot in high build automotive primer..

 

..the lower nose under the spinner has been left as it's a complex scalloped shape

 

 

 

 

 

 

 

 

..still lots to do, but the base form is starting to take shape..

 

TTFN

Peter

[CJP]

Looks very neat

[k5054nz]

Nice work Peter, she really is shaping up nicely.