Help - Covering 30% Pitts Special

[Stuart Palmer]

The wings and airframe of my 30% Pitts S-2A Special are now largely complete , now contemplating gathering material to start covering it.
It will run a petrol engine of at least 60cc, or preferably larger along with a smoke system so I'm naturally keen to ensure that the covering is proof to both of those.

I did look, albeit briefly at Solartex and then painting it, but it would appear that Solartex is not suitable for any cellulose paints or in fact any paint that isn't manufactured by Solarfilm Ltd.

Can anyone recommend a suitable covering for my Pitts that is safe for the fuels I have in mind?

Many thanks

[Phil Clark]

I did look, albeit briefly at Solartex and then painting it, but it would appear that Solartex is not suitable for any cellulose paints or in fact any paint that isn't manufactured by Solarfilm Ltd.

Can anyone recommend a suitable covering for my Pitts that is safe for the fuels I have in mind?

Many thanks

RUBBISH.....cellulose can definately be applied to Solartex.......I've done it many many times with no issues what so ever. I've also applied solvent based acrylics, water based paints (Warbirdcolors), & enamels to Solartex..........personally, Solarlac is the LAST product I'd choose!!!!...nasty stuff.

However, on a model of this size, I'd suggest moving away from any of the 'iron on' fabrics and look are one of a number of fabrics that are applied more like nylon & dope (fixed to the surface with a paint on adhesive & dope) but then hear shrunk.

SIG Koverall, Ceconite (from Belair) or Diatex 1000 (from Skycraft) are the main 3........a brush on liquid adhesive is applied to the surface, the fabric is draped over and more thinned adhesive is brushed through to bond the fabric to the surface whilst pulling the fabric tight by hand to remove creases etc........once adhered all round, it's shrunk with a heat gun then multiple coats of non-taught dope are used to seal & stabilise the fabric. These finished DO NOT bubble and sag in the sun like Solartex does.

Phil

[Simon Willey]

I have sprayed all sorts of paint over Solartex. The best is 2k.You can still by it.
I have used Cellulose on many models as well covered in Solartex.. You need to add a bit of plasticiser to it to stop it cracking later on.
Just sprayed my 30% tiggy in the Plasicoat that BQ sell. No problems with petrol on it.

[Stuart Palmer]

Interesting about Solartex.

I shall research about the fabric dope covering and see what I can learn. Forgive my ignorance, is the finished surface smooth or can be sanded smooth to give the smooth glossy finish typical of the Pitts?

Thank you

[Phil Clark]

Gloss fabric cover aircraft may 'look' completely smooth from a distance, but close up, it's very common to be able to see traces of the weave of the fabric......

Achieving said smooth glossy surface on a fabric airframe is a little different to how you go about it on a smooth 'solid' surface where you should always work down to a finish by applying multiple coats with a good flat back between coats gradually working smoother & smoother with finer adrasive papers on each flat back......this way, a lot of the product applied to the surface is removed so the end result shouldn't have excessive amount of paint (& weight) on it.

On a fabric surface, if you flat back between coats, if this isn't done VERY carefully, where unsupported fabric touches sheeted areas (creating a pronounced ridge) along rib cap strips, fuselage stringers etc.... you can start to rub through the paint down to the fabric below.......go too far and you rub into the fabric exposing the weave ending up with fluffy fibres showing. If you want a smooth glossy surface with minimal weave showing, this means lots of coat of paint to fill the weave (not unless you apply multple coats of dope to partially do it before paint is applied) with a gentle flat back just to knock off any major imperfections between coats. Once done, the final gloss can be applied with a 'gloss clear' over the top as the last coat. Only main issue with this is that it's quite heavy as you are't removing much paint per flat back so in effect you're building up to a finish not working down to one.

Personally, I'd still apply minimal product, then the gloss coat and live with the fact the weave of the fabric can still be seen.......unfortunately, the weight of the paint doesn't scale down in proprtion to the weight of the model!!!

Phil

[stuart cotgrove]

I briefly owned this third scale Pitts with a Zenoah 62 up front. Flew very well.

This was solartex sprayed with cellulose. The weave was not filled but looked very real and glossy too

[Peter Clare]

See the entries on nylon covering on this page of Technical Help Needed. It is directly related to your question. Regards, Peter Clare.

[Stuart Palmer]

I briefly owned this third scale Pitts with a Zenoah 62 up front. Flew very well.

This was solartex sprayed with cellulose. The weave was not filled but looked very real and glossy too

Thanks for the advice, just out of interest, what did your Pitts weigh?

[Stuart Palmer]

I bought a roll of satin Solartex and I've covered a small test piece and painted it using nothing more than off the shelf aerosol cellulose paint. No problems, as I was told there would not be.

I've also experimented with masking off as the surface of the solartex is not smooth I was concerned about bleed under the masking. At this stage I've only cheep DIY type masking tape and I'm now wondering is a better quality tape will prevent bleeding.

Has anyone any experience of preventing bleeding under maskings when painting on solartex?

[Tony Collins 1073]

This was posted by Phil Clark a week ago and you should find it useful.

Primer.....I'd stick to good old fashioned cellulose.......cheap & easy to use. Sourcing it can be an issue these days as many commercial paint stockist no longer carry much in the way of solvent based paints due to recent changes in legislation. I've seen 5ltr tins on evilbay, plus one of the local places to me in Gateshead can still get it.

With the colour scheme you have in mind, I'd go with a white primer rather than a traditional grey. Your white top coat will cover MUCH faster, and the white base will make the red nice & bright......some reds can turn a little deeper in tone with a medium grey primer.

Thinners....cellulose. The primer I use is normally thinned 60/40 (60 paint, 40 thinner)

Number of primer coats......I'd go with 2 with a light rub down between coats just to knock any imperfections off. Depending on how many coats of dope you've applied to seal the Diatex, this could also help fill the weave if you've been a little light on dope. Don't go overboard and be to aggressive with the rub down here as you run the risk or going back into the fabric on hard edges......I like using the fabric flatting pads intended for use on orbital buffing machines....used wet, these are very good and a little more gentle than wet & dry. 6-800 grade should be all you'll need.

Top coat.......over the past 4-5 years, I've become a real fan of water based top coats (namely Warbirdcolours.......I may be a little biased as I'm the European agent for this product....but hay ho!!) They are fast drying, very low odour and thinned with water makes switching between colours and final cleaning dead easy. This product is catalysed with a covalent bonder....once cured for 2-3 days, they are VERY hard wearing. The colours available are obviously all 'military' WW2 colours, but this does include a number of slightly different shades of white & red.

If you don't want to go the water based route, then I like solvent based acrylics for their ease of use, though the same problems apply to sourcing these as with cellulose....suppliers are fairly few & far between these days.

Both the water based & the acrylics give a satin finish....I assume you'd want a gloss, so I'd consider a gloss clear to finish the job and seal everything down. For me, there is only one to use and that's Klass Kote gloss clear. This is a 2 part epoxy based product. Stinks to high heaven, not cheap and quite time consuming to use (you can't just mix it & use it, you have to mix A & B together 50/50, wait 30-40 mins for the reaction to start, then add the reducer, then use it....and anything left over will be useless the next day).....but it does give a V good finish that is bullet proof to pretty much any solvent.

Masking....DON'T try and use cheap paper masking tape, it'll bleed all over the place, especially over fabric. Only use cheap paper tape to back off with newspaper.

For a model of this size, I wouldn’t paint the whole thing white then add the red over the top....the surface areas involved are large and it’ll add unnecessary weight. I’d mask the white, spray that, and then re-mask for the red.

All straight edges are best done with a plastic fineline tape (I use a 3M 6mm fineline tape)......slightly flexible, it will also go round corners as well. Plastic tapes seem to bleed a lot less than paper ones. For the tight corners in your scheme, I'd cut masks for masking film and combine these with the 6mm tape......they look pretty tight and it’s unlikely a fineline tape will go round them all without the odd crease.

The main tip I have when applying the 2nd colour to help prevent it bleeding under the tape is to go over ALL edges with the base colour (white in this case) first....this seals the edge of the tape, but if any paint does bleed under, it's the same colour as the base so will be invisible once the masking is removed. Let the base colour dry, then start on with the main colour.......light dust coats 1st just to get colour on the surface, followed with a final flow coat that once cured will give you the nice smooth finish. If you hit it with a heavy coat straight away and the white hasn't sealed the tape edges completely, the red may still bleed.....apply a couple of light dust coats first and the chances are dramatically reduced. Again, a gentle flat back between coats is a wise move to remove any imperfections, dust particles etc... that may have got on the job as you go. I'd generally expect to build the colours up in around 3 coats.

When removing masks, I never wait until the paint is 100% cured, I find if the paint is still V slightly soft, it leaves a crisper edge as the soft paint peels better than completely dry paint that can sometime chip. Always pull a mask off away from a painted edge whilst keeping the tape/film as flat to the surface as you can.

Hope that helps............

Phil