1/48 Testors Cessna O-2A Skymaster

[sunray]

Just Thought I would let you know how I got on. Here is the acrylic varnish I used which I got from B & Q (diy store in the UK).



And this is what I used to polish at a lower speed.



Here is the result you get.



I made a canopy with the polished plug but I didn't have any of the PETG plastic of the same thickness of the one I made with the unpolished plug, so I had to use a thicker piece.

The CA glue works perfectly in filling in holes and small repairs on the plaster then allowing the plaster to be polished. The varnish enables the plaster to be polish to a high sheen which I thought would be excellent for diorama builders as when polished the plaster looks similar to white marble and its cheap.

I made the vacuum formed canopy and I thought the varnish might protect the detail on the plug when you try to separate the plug from the canopy, but sadly not. So I found using plaster as a plug I would need to make a new plug for each canopy which is no problem as the plaster is cheap, easy to get hold of and cures quite fast.

I thought the varnish having a high temperature rating would work but I had mixed results. On the new vac canopy you get a residue left on the inside which is from the varnish but the good news is that it can be easily removed leaving a smooth finish but you can still see one or two imperfections left by the plug but not as many as without varnish.

So in conclusion if I was going to use plaster as a plug. If I was to use thin PETG plastic I wouldn't bother with the varnish but on thicker PETG plastic I would because the thicker plastic amplifies any imperfections like a magnifying glass in the plastic. Next time I think I will have a go at using car filler as a plug for a canopy and see how I get on.

To finish on a positive note I have really enjoyed experimenting with using plaster, also casting moulds with silicone rubber, etc which is really fun and easy to do. The hardest part was finding the bits of Lego as my lads are teenagers now and borrowing my wife's kitchen scales. I also find that now if I loose or damage a kit part and I can't get a replacement I can always have ago at making my own.

[sunray]

I have just made a plug from car filler (Isopon P.38 Easy Sand from Halfords UK). You have to mix it with a touch of harder, its a bit thick as you would expect for car filler and it stinks. It is styrene based and cures in about 10 minutes. It comes out of the mould without any problems and it doesn't look too bad. There are one or two bubble holes but they can be fixed with CA glue. I am going to leave over night to fully cure just to be on the safe side and have a go with the vac former tomorrow. I will let you know how I get on.

[Hosbabon]

What a fantastic build you are undertaking ! Great work

[sunray]

Thanks mate. This is the car filler I used.



In the box is a 60ml tube of filler and a small sachet of harder which cost about £5.50. You only need a small amount of filler so this should last me a while. I followed the instructions which were straight forward and mixed it on an old tile using a wooden ice lolly stick a put it in the mould trying not to create too many bubbles in the mould. I put it to one side and waited for it to cure which took about 20 minutes. The filler does smell a bit so I would mix it in a ventilated area or as I did it in front of my spray booth. Once it hardens it just a case of removing it from the mould which was easily do with no damage to the mould or new plug.







As you can see there were still a few holes caused by bubbles but these were sorted using a few drops of CA glue on a cocktail stick and lightly sanded. As with the other plugs I tidied the edges up and on it went to the the vac former. The plug was a lot stronger than the plaster one but the only thing I was worried about was how would it react to heat. It took a few minutes to make the canopy on the vac former as always. Then it came to removing the canopy from the plug which was easier and faster than the plaster and no damage was caused at all to the plug. The only problem was this when the canopy came off the plug.



Oh well back to the drawing board I thought. The plug has melted to the canopy. But on a closer inspection I noticed it wasn't burnt on it was just a residue off the plug and could be rubbed off was a cocktail stick. So using Tamiya Coarse Polishing Compound and a cotton bud I polished off the residue.



Here is how I got on.





I also noticed the shiny appearance of the plug had gone but this was restored by buffing it.



You can just make out the buffed surface on the right and the un-buffed on the left side. All that needs to be done now is to tidy up the new canopy and thats where I am off to do now.

[sunray]

I didn't like the look of the kit landing lights so I decided to see if I could do better. I used a bit of thin plasticard to cover up the seam lines of the wings in the light housing and for the lens I am going to use scrap bits of acrylic rod. Using a razor saw I cut the rod to roughly the size I wanted and then with the saw again I cut the rod in half giving me two half moons. I then filed the lens to size and drilled a small hole in each one to act as a bulb.



Then I glued each lens to the wing using thin CA glue and once they had cured I filed, sanded and polished them to get a good shine.





With that done I painted and weathered the inside of the cabin roof. Once that had dried I glued the wing to the fuselage. This being an old kit I was expected a few gaps and I was right but these are easily sorted by using plastic shims and filler.









With the wing attached then came the booms, tail plane, rear engine cowling and rear engine exhausts which again I used a syringe needle for them. The booms and tail plane were attached to the fuselage and went together easier than I expected as did the alignment. There were a few gaps but again I used plastic shims, etc.



















What I will do now is let everything cure and harden overnight and then it will be time for a little sanding. While I was waiting I made the gun sight but I had a problem as I couldn't find any photo's of a sight. That was until my mate Tony of the Connecticut Air & Space Center came to the rescue. The guys there are restoring an O-2 and he kindly took a few photo's for me, what a star!



From this I had ago of making one from plastic right angled rod, a small plastic disc and thin clear acrylic from the packing of the collar on a new shirt.











Not perfect but it will do. I am sorry about the photo's but my camera was having problems with it being so small.

[snapper_city]

Loving this build.

[Radleigh]

Me too, it's fantastic... Did you need any release agent in the mould when using P38? Never thought of using that, I have tonnes of the stuff... have put off making a mould for the reason of not having anywhere to mix resin.

Look forward to the next instalment.

[sunray]

Thanks lads.

Me too, it's fantastic... Did you need any release agent in the mould when using P38? Never thought of using that, I have tonnes of the stuff... have put off making a mould for the reason of not having anywhere to mix resin.

Look forward to the next instalment.

No I didn't use any release agent. The moulds are so flexible that the plugs nearly pop out. The problem with P38 is that it can't be poured as its so thiick so you have to be aware of bubbles. I hope this helps.

[modelling minion]

Love the gun sight, great attention to detail.

This build is really coming together now and it looks great, I am really looking forward to seeing the finished result.

Craig.

[sunray]

Thanks Craig. Here is the sight glued into place.

I next attached the wing struts, skips and a rectangular panel under the fuselage. I did plan to use the kit panel but I glued it on the wrong way round so I filed it off and made a replacement. After that I sanded down a few gaps.









With them done I could finally attach the glass. The windscreen was attached using first thin CA glue and then PVA. The good thing about vacuum canopies is that they a flexible which allows me to reduce the gaps at the sides where the windscreen joins the fuselage. Then it was just a case of gluing in the rest of the glass. To finish off I made the curved antenna from bent copper wire and used CA glue to attach to the fuselage. I did this because I looked at the kit part and it did look too strong.

[Spookytooth]

Very good work Ian, I like the tutorial on vac forming.

Simon.

[sunray]

Thanks Simon. I haven't done much lately due to watching the Rugby World Cup. I managed to get tickets to watch the "All Blacks" play Tonga at St James Park in Newcastle, absolutely fantastic. Any way here is what I have been up to. The detail on the under-wing stores, the miniguns and rockets wasn't much to write home about so I thought I would tidy them up a bit. The minigun pods where just tubes so I re-scribed the panel lines and using a few bits of brass tubing and CA glue I added some gun barrels to add a touch of interest.







The rockets that came with the kit weren't very good as you can see below.



So they had to join my spares box. The photo in the kit instructions had rocket pods attached so I ordered a resin set by Czech Masters.





You get six pods in the set but I only need two but i think the rest will come in handy in the future. You do get pylons as well but I will be using the kit ones. To attach the pods to the pylons I removed the two plastic pins on the pylon that was to hold the kit rockets and sanded them smooth. Then I drilled a few holes in the pylon and using CA glue I attached two pieces of copper wire and went the glue cured I cut the wire to the length I wanted.





Then I assembled the rocket pods and I used the copper wire in the pylons to mark where to drill the holes in the new rocket pods. Here are a few photo's of the minigun and rocket pods dry fitted as they will be attached later on.





Next I made the pitot tube from a bent pin and syringe needle using the kit part as reference. I prefer to make pitot tubes, antennas, etc from metal parts if I can so they won't snap off later on; well thats the plan anyway. All that was left to do was to attach the fin antenna and a aerial mount then I masked up the glass using tamiya tape and maskol ready for painting.

[sunray]

I managed to do a bit of painting today. First I primed with Badger Primer then I did a touch of pre-shading with thinned Tamiya Black.







The good thing I like about Badger Primer is that it dries fast allowing you to get on and thats what I did. The base colour for the O-2 is FS 16473 ADC Grey and the closest I had was Tamiya XF20 Medium Grey. Just to lighten it up a touch I added a tiny amount of Tamiya XF2 White and I thinned to about 50%. The majority of the top of the wing is white with grey along the leading edge. As a rule I would spray the lighter colour first but on this occasion I decided to spray the grey first as it was easier to mask this way around latter on. I didn't use any masking tape at this stage as I just painted the top of the wing freehand allowing the grey to just overlap where the white is going to go, then I sprayed the rest of the plane grey.





Now out came the masking tape and I then sprayed the white and Tamiya XF 85 Rubber Black on the nose and tail.









I also sprayed the minigun and rocket pods.

[Jbbusybee]

Really nice, thanks for sharing

[AdrianMF]

Just caught up on this build.Nice to see the outside is looking as good as the inside! I've had the same problems with surface erosion when vac forming over two-part filler moulds.

Regards,

Adrian

[modelling minion]

Great progress Ian.

She is looking fantastic and the extra work you have put in all the way through really shows.

Keep up the good work.

Craig.

[sunray]

Thanks guys. Last few weeks I didn't have time to do much but when I got back to my shed, I got on with sealing the paint with a few coats of Klear and thats when I had a bit of trouble. The Klear had started to crack and split the white Tamyia paint but not the grey. I have had this before with Klear and I thought it was caused by the paint not being completely dry but this time no. The white XF2 has had over a week to dry. I have also thought it could be the air temp in the shed being too hot but when I was spraying the Klear it was 61 degrees F. All I can think of is the white paint itself as the grey XF20 wasn't touched. To get around this I left it over night and swapped over from the Klear to using Simoniz Clear Acrylic Lacquer as it dries fast to a hard gloss finish.

As I have said it was only the white that was affected.



To help remedy the problem all I did was mask off the affected areas and spray them with Model Air white with 20% Vallejo Gloss Varnish and a few drops of Vallejo thinner, all mixed in the airbrush cup. I didn't want to use XF2 again and the Vallejo mix hopefully would help fill in some of the cracks, give a soft gloss finish and also because Vallejo is a slightly a different shade of white it would add a bit of modulation to the white on the wing. If you know what I mean. Anyway that done on to the decaling. I used a mixture of the kit decals and the after-market ones which were straight forward to apply using Micro Set and Sol.









You can just make out where the crack were but a bit of weathering should sort that out.





I also added the decals to the rocket and gun pods.





I didn't add any decals to the props as they weren't very good so they were just masked and sprayed.

[snapper_city]

Good save.

[Tomjw]

An excellent recovery with the paintwork. She's looking good.

Cheers,

Tom.

[AdrianMF]

That was a strange reaction, good recovery though. Hope you don't have any more nasty surprises.

Regards,

Adrian

[sunray]

Thanks lads. Here are a few a few photo's of hows I am getting on. I gave the decals a coat of Vallejo's Satin Varnish and airbrush cleaner in a 50/50 mix to seal the decals. I added a touch of chipping around bolt heads and side panels. Then I made my oil wash from burnt umber, black and thinner. Due to the problem with the cracking paint I decided to add a heavier wash than I was going to. Oh well it all part of the fun. With the wash added it was just a case of a tiny amount of oil thinner on a cotton bud to spread the wash around. That done I gave it another coat of satin varnish again to seal everything and once dry I started to remove the window masks and add the stores using CA glue for the rockets and Extra Thin for the gun pods. The last job tonight was to add the props.

[Carius]

Fantastic upgrade.

Cheers

[Spookytooth]

A well sorted 0-2 Sunray.

It is a bummer when you get an unwanted reaction between paints and varnishes.

Still she is looking great.

Simon.

[Tomjw]

She looks superb. Very nice.

Cheers,

Tom.

[Ex-FAAWAFU]

That is looking mighty fine. Since I can barely make out the white cracking in a close-up photo after your excellent save, it seems fair to assume that it will be invisible in real life.

I knew next to nothing about this aircraft before you started this build. Thanks!