...survey..

[Bootlegger]

    Guy's that are using dope to finish their models, what are you using, nitrate to start or butyrate from start to finish and why this way??   
 Thanks Gil

[Jim Catevenis]

I always start the finishing process with Nitrate dope and Nitrate filler followed by Butyrate.  The reason I do this is that Nitrate dope has more adhesive strength than Butyrate and whatever fillet material I use will adhere better to the Nitrate dope. 

Jim Catevenis
AMA 23801

[Neville Legg]

I use sanding sealer on all wood, that's everything, cap strips etc, about 3 coats, sanding to a smooth finish, then put the silk on with thinner, and the tissue on all wood parts. I only dope the loose silk with shrinking butyrate, until it's tight, then dope everything with non-shrinking butyrate, sanding in-between, sanding sealer doesn't shrink, and sticks well to bare wood.

Cheers

[Brian Massey]

I understand that Nitrate has more solids than Butyrate, so I start with that to fill in the wood. I go with butyrate tautening for the finish. I'm going to try Rand-O-Fill from aircraft spruce on my next plane. I've heard it is a good filler.

Anyone care to comment on Rand O Fill?

Brian

[Allan Perret]

I understand that Nitrate has more solids than Butyrate, so I start with that to fill in the wood. I go with butyrate tautening for the finish. I'm going to try Rand-O-Fill from aircraft spruce on my next plane. I've heard it is a good filler.
Anyone care to comment on Rand O Fill?
Brian

I have a can of that Rand O Fill but havent tried it yet.  Just read the label.  It is non-taut buty with aluminum powder to provide UV barrier for aircraft fabric (full scale I guess).  Opened the can for 1st time, its silver. Should be a great primer under a siver base for candy or metallic topcoat.
 
I am in the finishing process on an ARC SV-11.  Was planning to start shooting some filler coats of automotive primer surfacer on it this afternoon.  I might give this Rand O Fill a try instead.  I was thinking I might add some zinc sterate to it also.   The parts of the SV-11 I am getting ready to prime will eventually be white, so I was going to use a white surfacer.  Can try a coat or 2 of the Rand O Fill to see how it fills and sands, then finish with coat of white surfacer.   

[FLOYD CARTER]

After just too many paint failures using mixed media, I start and end with Brodak butyrate, as Windy advises.  No more surprises!  Sure, it takes more coats in preparation, and a couple more clear coats at the end, but it always turns out just fine.

Floyd

[Tim Wescott]

It's been years since I've done a comprehensive finishing job (lately I've been doing rattle-can and plastic film on big planes, tissue & clear dope on small ones).

But I've always used Sig butyrate throughout the process, and have never had problems.

[Bill Little]

Hi Gil,

Many years ago Mr. Bob Hunt told me about Randolph's Non-Tautening tinted Nitrate.  Ever since then I have used it up to and including attaching the covering.  I find that it takes less coats for prep (builds up fast) and the Nitrate seems to stick the covering better be it Silkspan, Silk, Polyspan, or CF veil..  On my Vulcan I did use nitrate as the "filler" with nothing added.  Several years later and no grain, plus it was LIGHT.

Once the model is completely covered I switch to Sig Supercoat clear (shrinking) on the open bays to tighten up the covering.  Then it is Sig Lite Coat Clear (non tautening) for the rest of the job until the colors go on.  I put Zinc Sterate in the Lite Coat for filler, or use automotive primer to fill the paper.  (I also use Randolph's Butyrate products in the same "families" when I can get it)

The colors and final clear can be one of several systems.  Mostly I use automotive acrylic lacquer for colors and then Sig Lite Coat clear for the final coats.  Sig, Brodak and Randolph butyrate colors sometimes along with DuPont Chromabase.  Just do not put clear dope of any kind over the raw Chromabase colors.  However, I have also used quite a bit of Automotive 2 part clear polyurethane for the final clear coats (and have to when I use the Chromabase colors).

This is a kind of convoluted system, but it has always worked for me.  I just remember to never put Nitrate over anything else!

Bill

[wwwarbird]

 50/50 butyrate/thinner from start to finish for me.

[Neville Legg]

Ty, that's why I use sanding sealer first on all the wood, it doesn't pull and shrink the wood, and fills the grain after a few coats, sands beautifully, and re-activates with thinners when laying tissue over it. Do you get a liquid finish called banana oil over there in the US? I don't know what it consists of, but gives a lovely gloss finish on my free-flight models for very little weight gain, and doesn't shrink.

Cheers

[M Spencer]

Butrates he high shrink that pulls tissue up from corners, like wing / stab to fuse joints.Also low adhesion.
And used alone & throwing on ten coats in a day , will continue twisting things for decades , or over 18 months anyway.( due to the suface sealing and impedeing the gassing of of the chemicals )
ALSO Nitrate wont go over butrate, so if youre useing both , start with Nitrate .

Good way to asphixiate yourself is sleep in the wagon  with a large just covered stunter in it .
A 10 mile walk will start to cear a few braincells to functioning point.dont let the Methanol leak in the camper , either

[Neville Legg]

Ty, I don't know what the sanding sealer consists of, it says nothing on the can? It's made by the same company that makes most of the clear dope over here, H. Marcel Guest Ltd, (HMG Ltd) they've been making dope since the before the war. They make the banana oil too. I wish I knew what was in the sanding sealer, I've tried making my own with talc and dope, but it's never been as good as the manufactured stuff. Butyrate and Nitrate seem to go over it well, no adhesion problems at all. There are cellulose and non-cellulose sealers, this one is cellulose, obviously.
There is a company over here (5 Star Ltd)  that make a shrinking clear dope that has no smell, and they claim its far superior to the old styles of dopes? Google their site and read the blurb!

Cheers