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A pair of Airfix Hawks in 1/72. Finished.


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On 19/04/2017 at 11:38 PM, limeypilot said:

They'll be spectacular WHEN they're finished......

 

Capitalisation acknowledge Ian - and am full of good intentions to crack on now.....after I've got back from a quick trip to London today/tomorrow to see Tamsin Grieg in Twelfth Night and a nice

breakfast at the Wolseley.....

 

On 20/04/2017 at 7:29 AM, giemme said:

I'm afraid I'll have to disappoint you :shrug: It is quite ordinary - and rather messy, see for yourself:

 

Ah - but marvels from it do appear.   Oh and it looks like the garage is your Britmodeller's spray den of choice.  Obviously taking all of the precautions of which @Miggers would approve....

 

12 hours ago, TheBaron said:

Seeing your workspace there Steve brings home to me the wisdom of actually having a lid on your box of 'parts I'm waiting to use', a factor which has become abundantly clear in the last few days...

 

I'm slow - but I did eventually learn from bitter experience wrestling with the carpet monster.

 

12 hours ago, Tomoshenko said:

Steve, while it would be a pity to cover up those lovely exquisite pitots, have you considered adding a sheaf and one of those stripy RBF tags to one of the Hawks as per the piccie above? It would look the business.

 

Hmm.  P'raps I should think about decking the wrap-around camo Chivenor Hawk with a set of RBF flags/pins etc.  It might be a nice contrast to the camouflage.  I s'pect such things can be purchased or printed.

 

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2 hours ago, Fritag said:

Hmm.  P'raps I should think about decking the wrap-around camo Chivenor Hawk with a set of RBF flags/pins etc.  It might be a nice contrast to the camouflage.  I s'pect such things can be purchased or printed.

 

 

They can, though the only commercial ones I have seen tend to be the US version with REMOVE BEFORE FLIGHT written on them, rather than the simpler red-and-white stripey jobbers that you and I remember from our youth.  

 

I have made up a sheet of lead foil painted appropriately - yet to try trimming it to size, so it could all go horribly wrong, but I am hopeful.  A man of your calibre...

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2 hours ago, Fritag said:

Oh and it looks like the garage is your Britmodeller's spray den of choice.  Obviously taking all of the precautions of which @Miggers would approve....

Precautions? :) It's larger than it seems (around 70 square meters) and well ventilated, plus I'm using a mask :winkgrin: 

 

2 hours ago, Fritag said:

 I s'pect such things can be purchased or printed.

Both. I bought the Eduard RBF PE set in 1/72 for my F-4C build, but also printed out some on regular paper (double sided, obviously), coated with Future (or PVA, can't remember now) and bent to shape accordingly.

 

Ciao

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The mini-est of mini updates - just to show Bill that I too am still broadcasting; and to riposte à hendie :) (this only makes sense if you're familiar with Bill's Wopsie thread I'm afraid....)

 

Begun the detailed painting on the seats with the yellow of the hard PSP (personal survival pack) seat base - it's mostly covered with a black cushion so only a glimpse of the sides here and there is visible:

 

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I plan to have the the two rear seats fitted with solo flight aprons which'll cover all this work - but I figure that if I detail paint all four of them then I increase the chance of two of them being half decent :)

 

And I've spent some time prepping some canopy components ready to make a silicone mould from:

 

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I vacc'd a test canopy a long time back - but I think I can do better.  Once I've got a silicone mould I'll cast some resin - and maybe plaster - copies to use as male masters.

 

I've found that resin masters tend to discolour clear vac formed sheet  (but also found that if you do a few you stand a chance of getting one that hasn't discoloured) hence I thought I'd give plaster a go.  Any better suggestions gratefully received....

 

There - not much done - but something!

Edited by Fritag
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Would painting (I'd guess preferably with gloss paint) the resin masters stop said discolouration Steve? Or make it worse...? As to the plaster I read somewhere a recommendation to use dental casting plaster rather than regular plaster of paris as it's apparently smoother & harder (cue @CedB...) and thus more suited for vacforming masters. I bought some for this very purpose, but of course haven't got round to using it.

 

Nice to see the return of Grommit & his siblings...!! :winkgrin:

 

Keith

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Should we fnaaar a few for Keith while Ced's on form

 

Nice to see the yellow bits coming into consideration Steve, I thought they must be hard plastic

 

No fun for long sorties huh

 

I will echo Keith's suggestion of using dental plaster if you make moulds for the canopies

 

Then you can tell us how it went and we can all lay in some stocks

 

 

 

I really do loves them Gromits

 

ta mate

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4 minutes ago, keefr22 said:

Would painting (I'd guess preferably with gloss paint) the resin masters stop said discolouration Steve? Or make it worse...? As to the plaster I read somewhere a recommendation to use dental casting plaster rather than regular plaster of paris as it's apparently smoother & harder (cue @CedB...) and thus more suited for vacforming masters. I bought some for this very purpose, but of course haven't got round to using it.

 

Nice to see the return of Grommit & his siblings...!! :winkgrin:

 

Keith

 

I'll google dental plaster ta Keith.

 

I've tried painting resin masters before without much success.  Even tried gloss radiator paint! The paint didn't react well to the heat.  I think it must be something to do with the heat retention properties of the resin.  IIRC @Cheshiretaurus has had the same issue with resin casts.

 

 

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12 minutes ago, keefr22 said:

Nice to see the return of Grommit & his siblings...!! :winkgrin:

 

Ok so: Grommit - cheese - cheese eating surrender monkeys (sorry) - alpha jet - hawk v alpha jet rivalry.  Funny how the old brain works innit?

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On 21/04/2017 at 0:20 PM, Ex-FAAWAFU said:

They can, though the only commercial ones I have seen tend to be the US version with REMOVE BEFORE FLIGHT written on them, rather than the simpler red-and-white stripey jobbers that you and I remember from our youth.  

 

Ah yes - actually as I think about it - unless I fit CBLS - which I weren't planning to, I'm not sure if and where there'd be any stripey jobbers.....

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9 hours ago, Fritag said:

 

Ah yes - actually as I think about it - unless I fit CBLS - which I weren't planning to, I'm not sure if and where there'd be any stripey jobbers.....

 

The 100 sqn & FRADU (If that's who they still are?) jets in the static at Fairford last year had one in each u/c leg. They also had olive coloured fabric intake covers with one on each. The 100 sqn machine also had a dainty brass padlock on the canopy opening handle....!! (no RBF tag on that though, as I suspect it would be difficult to fly the jet without removing it...:whistle: :D)

 

Keith

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Great to see some detail painting going on, Steve :clap: I have no clues about the resin master subject, but if it is a heat retention matter, can you try and fit some metallic bit in non relevant areas, to act as heat dispersors?

 

Ciao

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35 minutes ago, keefr22 said:

The 100 sqn & FRADU (If that's who they still are?) jets in the static at Fairford last year had one in each u/c leg. They also had olive coloured fabric intake covers with one on each. The 100 sqn machine also had a dainty brass padlock on the canopy opening handle

 

Ta keith - I'll have to check references.  I don't remember seeing pins being in the undercarriage on the flight line - but I could easily be wrong.  I expect the fabric intake covers are land-away gear.  IIRC the usual intake covers were flat fronted and fitted mostly inside the intake.

 

24 minutes ago, giemme said:

I have no clues about the resin master subject, but if it is a heat retention matter, can you try and fit some metallic bit in non relevant areas, to act as heat dispersors?

 

I think CT tried mixing in some aluminium powder with his resin for that reason.  Can't remember with what results.  I guess if I have problems with discolouration I could experiment with hollowing out the resin master a bit and filling it with liquid gravity or some such.  

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Liquid gravity? Does that come from Krypton? :D Sorry, I don't know what that is :shrug:

 

In my sole attempt at vac-forming, the master was metallic (pretty simple stuff, it just needed to be bent in a curved shape), plus I placed it on top of a bolt+nut to keep it flat to the vacuum plate. Plenty of heat dispersion there, and all the vacformed parts remained clear.

 

Ciao

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I wonder if you are up to trying a radical substance to cast the master

 

I'm thinking of getting some clear resin to cast with soon, might be worth giving some of that a punt

 

After all no colourants may be no discoloration either

 

Giorgio Liquid Gravity is a Perfect Products er product which is made up of zillions of little lead balls that are dispensed from a nozzle bottle rather like a large Vallejo pot

 

I suggest a Googleing will come up with a picture

 

And a willing vendor

 

I used it inside my tail dragging Catalina and because it flows as you pour it dropped down inside and vanished, if travelling makes it roll to the back of  the fuselage it is a simple matter to tilt it forwards and let gravity be useful (for a change) the nose now sits nicely on its wheel

Edited by perdu
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On 25/04/2017 at 1:01 PM, perdu said:

I wonder if you are up to trying a radical substance to cast the master

 

I'm thinking of getting some clear resin to cast with soon, might be worth giving some of that a punt

 

After all no colourants may be no discoloration either

 

Interesting thought Bill,

 

I like the logic of that thinking - and seeing as I'm no chemist I can't refute it - and anyways i quite like the idea of having some clear resin on the shelf for use with making bits and bobs like the Strobe lights etc.

 

All I've had time to do in the last couple of days is get the canopy masters ready for casting.

 

I spent a therapeutic(?) session sanding off the framework and micro-meshing the canopies nice and smooth.

 

Then mounted em on a plasticine bases ready for pouring the RTV silicone.  I wanted the bases to be of a size and shape to make (1) a generous reservoir for the pouring resin - I've found this is the best way (short of a pressure chamber) in minimising the problem of air bubbles -(as there's plenty of room for the bubbles to float to the surface) and (2) provide a well shaped base for when it come to Vacc forming.

 

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RTV mixed and nice neat lego mould.  Look at all those air bubbles :mellow:

 

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Half filled mould.  I paused at this point for a few minutes, to let as many air bubbles as were willing rise to the surface and pop, before pouring in the rest of the RTV.

 

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The RTV was still a bit tacky this morning.  Hope it's going to cure good and proper......:blush:

 

The  talk of remove before flight flags got me thinking again about fitting a pair of CBLS to the Chivenor 63 sqn Hawk.   I'm not sure whether to or not - but in case i decide to fit em I thought I'd do a bit of basic prep.

 

I have the Flightpath white metal CBLS  but I can't get on with white metal bits so I decided to cast a copy in resin - which I can then work on to see if I'm happy with it; and if I am, I can then cast a couple of copies of that to use on the model.  With me?

 

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Given the last batch of RTV was still tacky I used some microscales (as recommended by @Cheshiretaurus  in his thread on home-brew PE) to get the ratios exactly as per....(I've done a lot of RTV/resin casting now and I guess I was getting a bit slack about the exactitude of my measuring.....):

 

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Hopefully when I get home tonight all the RTV will be cured.......

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1 hour ago, Fritag said:

Hopefully when I get home tonight all the RTV will be cured.......

 

I have found that exact measurement only really matters when you are mixing small quantities of silicon and/or resin. As long as you are in the ballpark, chances are good that it will cure. It may cure faster or slower depending upon the ratio, but it does cure.    I think age is more concerning (not mine - the resin/silicon) - I found that when resin gets past a certain age, one of the two parts gets decidedly crusty.  My last batch of silicon went all weird on me... it still cured but it was like trying to mix toffee.  Herein, forthwith, and from this point forward, I shall only be purchasing smaller quantities of resins and silicons

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4 minutes ago, hendie said:

 

I have found that exact measurement only really matters when you are mixing small quantities of silicon and/or resin. As long as you are in the ballpark, chances are good that it will cure. It may cure faster or slower depending upon the ratio, but it does cure.    I think age is more concerning (not mine - the resin/silicon) - I found that when resin gets past a certain age, one of the two parts gets decidedly crusty.  My last batch of silicon went all weird on me... it still cured but it was like trying to mix toffee.  Herein, forthwith, and from this point forward, I shall only be purchasing smaller quantities of resins and silicons

 

This accords with my experience which is why I may have been a bit slapdash mixing last night's batch.  But it's also the case that I've had the silicon for quite a while so maybe age (not mine - it's) has something to do with it.  I've now used the last of the catalyst anyways so I've had to order a new batch.  I've gone for 500g of silicon and this time for a 'green' catalyst (which is purported to cure in a third of the time of the red that I've generally used).  I might chuck the little of my last batch of silicon away now - probably about 100g of it left.

 

As to the two part resin mix.  I decant small quantities of part A and B into eye dropper bottles which I find useful as i can then mix small equal quantities by number of drops (works a treat).  But the price to be paid is that after a period of disuse the eye dropper bottles crust up/gum up and have to be thrown away.  S'worth it tho'.

 

I decant a lot of stuff such as thinners various/flow enhancer/klear/rubbing alcohol etc into eye dropper bottles (generally 30ml size) for convenience.  I get the bottles cheaply on eBay.

 

 

 

 

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And suddenly............nothing happened :blush:

 

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Last night's RTV silicone is still a bit tacky (but being positive about it, it does seem closer to being fully cured than it was this morning) and this mornings carefully micro-measured stuff ain't cured yet.

 

I'm thinking (ok hoping) that hendie's right and it'll get there sooner or later; and I'm thinking (ok guessing) that he's right again and the reason it's being recalcitrant this time is that it's past it's prime so to speak.

 

So this is the BM post equivilant of watching paint drying :) Not sure it'll catch on......

 

 

 

 

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Hi Fritag,

 

Fascinating stuff, as always, the time/effort/skill you guys put in to these projects never ceases to impress me.

 

What's the temperature like - these materials are exothermic when they cure so can get noticeably warm, but if they are cold to start with they don't really 'get going', as it were.

 

Gentle warmth, like an airing cupboard, may help...

 

Good luck with that and we look forward to seeing the results

 

To assist with de-bubbling, if you don't have a vacuum chamber (hasn't everyone got one of those?) then a vibrating plate will help you. Get a small electric motor and put an eccentric weight on it ( the metal part out of a 'chocolate block' electrical connector is brilliant for this, put the motor shaft in where the wire would go, make sure both screws are tight or they'll get flung off) Then attach said motor to a base plate - I use an offcut of MDF, balsa, whatever is available. Place that on a sheet of foam rubber on your bench, and the mould on the vibrating plate. After you've poured the silicone in, switch on the motor and after a couple of minutes all the bubbles will have been 'encouraged' to the top. 

 

BTW a heck of an undercut on the canopy moulds, will they come out of the silicone OK do you think?

 

Cheers

 

Geoff

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My guess is yes, they will extract from the moulds OK

 

If Steve intends a vac or pull mould from these masters (he does I think) he needs a decent undercut to give definition to the moulded bits

 

I read in the Tools and stuff section (at the back of the website, just past the cafeteria) that using the compressor inlet as a vac source should help degas quite nicely

 

I intend giving it a go with my fridge motor compressor next time I do some moulding, might be worth a punt next time for you too Steve

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