1/18 Scale Blue Box F4U-1A Corsair Modification

[dodgem37]

'Y'all really liked that last post judging by the comments.  Is it transparencies?'

For me, it's a cumulative effect.  Not one thing.

 

Another.

 

Sincerely,

Mark

[JayW]

4 hours ago, dodgem37 said:

For me, it's a cumulative effect.  Not one thing.

 

 

Looky there!  It specifically says that is its purpose.  I think I might try that.  Thanks Mark! 

 

7 hours ago, Maybach_man said:

In the UK :-https://www.amazon.co.uk/Toluene-Solvent-Thinner-99-9-Pure/dp/B08T1B5PS4

 

Wow!  Pure Toluene.  I didn't follow through with ordering, but I suspect I will meet with a roadblock.  There must be reasons it's so hard to get on this side of the pond....  Will hold this in reserve.  Thanks gents for you suggestions.  That's why I love LSP.   

[easixpedro]

36 minutes ago, JayW said:

 

Looky there!  It specifically says that is its purpose.  I think I might try that.  Thanks Mark! 

 

 

Wow!  Pure Toluene.  I didn't follow through with ordering, but I suspect I will meet with a roadblock.  There must be reasons it's so hard to get on this side of the pond....  Will hold this in reserve.  Thanks gents for you suggestions.  That's why I love LSP.   

Check your local paint store like Sherwin Williams or PPG.  Ace Hardware might carry it in their paint aisle too.

[Pete Fleischmann]

Here ya go:

Click me

 

cheers

P

[JayW]

Thanks all for the continuing suggestions WRT contact cement, and thinner.  This is all, of course, in support of my decision to skin this beast.  I still don't know for sure what I will do ultimately.  But I am getting smarter: 

 

One, the Weldwood general purpose contact cement, available in big hardware stores like Home Depot, seems to work great.  Not only that but it is not overly thick, so it brushes on nicely.  As long as it isn't too old.  Still, I have on order some Evo-Stik - the stuff Airscale (Peter Castle) uses and swears by. 

 

Two, thinners - per the suggestions of more than one on various forums (not this one though), I used mineral spirits to thin down some Weldwood contact cement.  It mixed very well.  No lumps.  But what that did was to ruin the adhesive qualities of the cement, totally.  Next, I think, will be some Bestine.  Stay tuned on that.

 

Ok, some progress on the Corsair is being made on three fronts - the firewall, aluminum skin panels, and the oil tank.  Before I describe, I want to say that my patience is at an end joining up the center fuselage with the center wing.  It's been months upon months working to achieve this big milestone.  And it still eludes me.  The one thing standing in the way is skinning as much of the center fuselage as I can.  Why?  I am finding that skinning is a bit heavy duty modeling, with vigorous sanding and burnishing once a panel is installed.  It scares me to death doing hard work like that on a big unwieldy assembly with landing gear struts and doors hanging out in the open begging to be broken off.  So I must minimize the risk - I am going to skin as much of the fuselage as I can prior to joining it to the wing.  Bear with me please.  What a milestone that will be!

 

About that firewall, here is what we are talking about (from Bell volume 1):

 

     

 

Note that the firewall is kinked about 20 deg.  Also note the panel attach flanges with Dzus fastener holes.  Also note also that the lower edge interfaces with the top of the spar.   That is a tough interface.  In a post not long from now, you will see how that goes.  Also note the oil tank, and compare it to the one I computer modelled (see below).  Lastly note that the cheeks of the lower firewall house all the various systems penetrations from the fuselage proper to the engine accessories compartment.  A big deal.

 

First I had to add in the panel attach flanges for the big engine accessories panel just forward of the firewall:

 

  

 

Note that I have included little magnets (those little silver wafers).  I sure hope my plan for removable engine cowl panels works!   

 

I spent literally days researching those systems penetrations.  Sorting out the right ones for this particular vintage of F4U (they changed quite a bit), and figuring out how to model them - what materials, and where.  When that homework was completed, I began work on the lower portion of the firewall.  What you see below is my 4th try on a web periphery that matched the fuselage IML, the top of the spar, and the upper firewall portion.  And of course the system penetrations and bulkhead fittings:

 

 

Just wait until it gets installed - it's going to be awesome.  Here is a little dry fit preview:

 

 

The oil tank - Around the corner will be the engine accessories compartment.  I cannot tell you how big that is going to be.  But I need complex parts to make it happen, and many will be 3D printed.  The oil tank is one of those items, so I needed to get it designed and sent off to Tim to get printed and sent back. 

 

Here it is:

 

   

 

 

It isn't perfect, but FAR better than I could have done with any other method.  Note this tank is larger than the one in the Dana Bell picture above.   For whatever reason, Vought increased the capacity of the oil tank, and then had it retrofitted back to earlier made aircraft in the field.  The ends were incredibly hard to model on Rhino and I will not bore you with the details.  

 

On the third front was continued skinning work.  Please recall that what i have used so far to skin has been .005 inch thick ANNEALED aluminum sheet.  This stuff is very soft, and just will not do well with big panels where any little imperfection will show up clearly.  Heat treated stuff is much more appropriate.  Airscale has been using litho plate for years, which is heat treated, and he offered to send me some.  As I wait for that litho plate to arrive from Peter (and so much appreciation for his support of my efforts on this project), I happened to read from another project where a modeler used soda can aluminum for skinning.   Soda can!

 

So I had to check that out.  Here is a panel I made for the FW-190 mule, made from a coke can:

 

 

Isn't that nice?  The stuff is pretty stiff, the paint sands off easily, and it bonds just fine with the contact cement.  So I just had to try it on the Corsair.

 

This is the panel I would try it on:

 

 

 

Installed:  

 

 

This worked pretty good.  There are a couple of "dents" that look worse than they are.  Keep in mind these panels will be painted.  Were it to be NMF, I'd do it over again.  Also, I found that punching all the little fastener circles tended to make the edges grow just a tad making it difficult to for the edges to lay down smoothly.  Took lots of burnishing, and some thin CA glue to get them down for good.  Again, NMF makes it look worse than it is. 

 

With that I thought I would attack the big center panel where the fuel tank access is, using coke can alum.  The story would be different here.  First, taping the fuselage and creating panel outlines.  Then transferring that tape onto the aluminum, and laying out cutouts and fastener locations, and punching.

 

And I got this (Imgur "huge" thumbnail for emphasis):

 

 

 

 

 We are going to call this panel and its door a prototype, where things can be learned about the process.  Some is good about this panel, and much is bad.

 

The good - It fits onto the fuselage quite well.  And....well that's about it.

 

The bad - some of the punches went all the way through leaving holes.  Deal breaker.  I used the punch on a cutting board, not glass like I did last time.  Bad decision.  Won't do that again.  Also, I created the fastener marks around the periphery of the circular cutout prior to scribing and cutting the cutout.  And got a bad case of "short edge margin".   Got a sequencing problem there which I will resolve.

 

Combine the bad items, and we have an un-useable panel.   That's OK, the second try is going to be much better. 

 

Just for kicks, here it is taped into place:

 

 

 

I hope you agree with me in that I see the potential for success.  The second one will be awesome, I think.

 

Now I wait for the mail from jolly old England, and work some more on the firewall.  Stay tuned - exciting things are coming soon.

 

     

 

 

 

Edited February 12, 2022 by JayW

[Oldbaldguy]

Dents:  Non issue.   All metal airplanes have ‘em here and there.  Nature of the beast.

[LSP_Kevin]

Superb update, Jay! You're doing wonderful metal work here. Tempted to try it myself some day.

 

Kev

[Out2gtcha]

Awesome!!

[dodgem37]

Good show.  'Nice problem-solving.

 

''Next, I think, will be some Bestine.'

Been using Bestine since the 70's.

 

Sincerely,

Mark

 

 

[Anthony in NZ]

Just speechless, your workmanship and skillset is clearly growing during this build, I love your approach and growth.  I am learning a lot and feel like I am being left behind all at the same time!

 

Well done indeed, another inspiring builder on here

 

Cheers Anthony

[Jim Barry]

Great work with the can. I have one saved next to my Bearcat but can't seem to jump in. I used metal tape on the fury (and a few bits of litho from Peter!) The tape does work some tight spaces pretty well and cuts very easily, of course.

 

 

[KiwiZac]

Pure magic!

[Rocat]

Amazing and beatiful work!

[JayW]

Mail from overseas is super slow, at least my package of litho from England is.  I could stand it no longer so I ordered and received some .005 inch thick heat treated aluminum shim stock from McMaster-Carr.  I think this might be just about the same stuff as litho, for purposes of skinning models.  We'll see.  One thing though - this stuff is far better than the coke can I used for the last skin panel I did (see last post).

 

Here, I re-did the failed center panel in front of the windshield, the fuel tank cover.  Here it is already with periphery cut, and fastener patterns laid out for awl punching: 

 

 

And the ready-to-install skin panel:

 

 

I am super pleased with this result.  I basically followed detailed instructions from Peter Castle (airscale).  It isn't all that different from manufacturing a real skin panel!  

 

Then same for the RH panel below it (the LH already installed is the one made from coke can - this is better):

 

 

 

Just about every rivet and bolt is represented.  The spot welds (the Corsair had alot of spot welding) are not.  One might or might not see spot weld marks on the real airplane....

 

The extent of the paneling so far:

 

  

 

I welcome comments critical or no.  I would like to say I am enjoying the skinning effort.  And in a way I am.  But the work is a bit tense - it's very labor intensive, and a late mistake can make one have to start over.  Bonding is a bit stressful too - it's messy, and there is a time element.  You have to be fairly quick, and these panels are large.  A mis-alignment can be kind of unforgiving.  

 

And I continue to find things to do before joining the wing and fuselage - the milestone I have been working toward for so long.  Here is work on the belly door (shown with the toy part it replaces):

 

 

 

 

 

The toy part of course lacks the internal structure; I added it per the engineering drawing, and it is surprisingly stiff.  Note it has louvered hinged side plates that fold and unfold depending on if the door is retracted or extended.  Mine will be extended.  It's function is to vent the engine accessories compartment.  This ugly thing (ugly on the real airplane too) is in a place where the "sun don't shine" so to speak, and I am going to have to install it before I get on with the engine accessories compartment, due to access issues.  This activity is on the horizon now, and you will see it soon after I join the fuselage and wing, and complete the cockpit.  I guess I will weather it further - in reality it could be the grimiest component on the whole airplane, with exhaust stains on the outer surface, and oil and hydraulic fluid leakage stains all over the inside, and outside too. 

 

I have a couple of big skin panels remaining, and then by gosh or by golly, I think I get to join fuselage to wing.  Coming soon; stay tuned!  

Edited February 20, 2022 by JayW

[airscale]

amazing Jay - I knew you would nail this technique

 

a couple more tips - if you are not already, always make holes before cutting out panels - it's so much easier when you have a lot of area to work with, rather than making up a panel detailing it and then making a hole. the other is get some 0000 wire wool so once the panel is finished & detailed, a gentle rub with wire wool deburrs everything and gives a great finish for painting - this can also be done on the model - just always work away from where you are holdingf the panel down or you can catch it and fold the panel back on yourself - tell me how I know...  lastly always wipe the panel down with adhisive thinners as when you use the awl through tape, you actually cut loads of little tape discs which can either stay in the rivet depression or can mar the surface when burnishing the panel after rivetting to get rid of pillowing & quilting

 

as you say, it is like real skinning, not only making it, but the look and feel of the finished result

 

love how it's going

Peter