Author Topic: I need a finish that will not shrink -Randolph Non shrinking dope? (Read 4000 times)

Walter Hicks · « **on:** July 10, 2012, 06:02:21 PM »

Hi Everyone,

I am in the process of building an Al Rabe Sea Fury. I have just completed sheeting the fuse. All of the surfaces are sheeted. I plan to use

.2oz Carbon Matt to cover it and use Basecoat /Clearcoat paint. My question is really directed for Bob Hunt, but I am sure he is busy up to his

eyeballs getting ready for the Nats. When the .2oz CF Matt is applied with Randolph non - shrink dope , does this really mean that literally?

If the dope shrinks very much at all I will be in trouble. The sheeting is light a grain wood and in most places covers a minimal structure.

It will be a while before the finishing starts.( A long while) Did I read somewhere that the latest and greatest method is to mix Epoxy

then put in on the surface and wipe it off , sand it then apply dope? This would make sense as it would stabilize the surface.

Anyone who is using this method place chime in. I have another plane I can cover to practice i.e. get experienced with this method.

Bill Little · « **Reply #1 on:** July 10, 2012, 07:55:13 PM »

Randolph's non tautening and Sig Lite Coat are the least shrinking of dope products as far as I know. But they still have a "slight" shrink rate. Any dope will shrink........

Bill

john e. holliday · « **Reply #2 on:** July 11, 2012, 07:31:02 AM »

Go back and read Al's posts on the other site. He uses epoxy that is thinned I beleive. Also with light weight fiber glass cloth. Or better yet just contact him. He posts alot on Stuka Stunt.

Alan Resinger · « **Reply #3 on:** July 11, 2012, 07:41:59 AM »

Walter,
On my last plane I used Z-Poxy finishing resin on the final sanded bare wood. Brush it on unthinned and then use paper towels to wipe it all off. Leave just the barest amount on. When dry, a coat or two of Nitrate dope followed by your Carbon Veil. Low shrink dope, filler and prime coat followed by your base coat/clearcoat. That is what Hunt does.
Alan

Walter Hicks · « **Reply #4 on:** July 11, 2012, 05:50:58 PM »

Thank you Alan, That is what I needed to know. I need a light strong finish. I appreciate all of the responses.

EddyR · « **Reply #5 on:** July 20, 2012, 05:07:09 PM »

The answer is so simple and it is right at your Auto parts store. Use Duplicolor clear lacquer. They have it in quart cans and it retails for $22 quart. It fills smoother and sand easy. It will not shrink or pull fillets and it sticks like crazy. Best of all it will mix with dope products . It is made for top coat on cars but use at least one coat of fuel proof dope as a finish coat. I have used it for a top coat and after a year of use it softened where exhaust has sat on it. I have been using it now for three years and it does just what you are asking for.
Ed

Bill Little · « **Reply #6 on:** July 20, 2012, 05:22:41 PM »

Quote from: Ed Ruane on July 20, 2012, 05:07:09 PM

The answer is so simple and it is right at your Auto parts store. Use Duplicolor clear lacquer. They have it in quart cans and it retails for $22 quart. It fills smoother and sand easy. It will not shrink or pull fillets and it sticks like crazy. Best of all it will mix with dope products . It is made for top coat on cars but use at least one coat of fuel proof dope as a finish coat. I have used it for a top coat and after a year of use it softened where exhaust has sat on it. I have been using it now for three years and it does just what you are asking for.
Ed

HI Ed,

Have you tried any of the "other" clears they have in the quart cans? They have a few mixes like pearl, flip flop, etc.

Bill

EddyR · « **Reply #7 on:** July 20, 2012, 07:11:44 PM »

Hi Bill I have not but they are the same formula?

Ed

Mark Scarborough · « **Reply #8 on:** July 20, 2012, 07:21:18 PM »

if its lacquer, it will shrink,, period,, no way aground it,, air dry products shrink,,,
epoxy, or even catalyzed urethane clear would be my suggestion

Bill Little · « **Reply #9 on:** July 21, 2012, 12:37:14 PM »

Quote from: Ed Ruane on July 20, 2012, 07:11:44 PM

Hi Bill I have not but they are the same formula?
Ed

HI Ed,

They are the same formula but with flakes, pearl, etc., added. It's for special effects on cars but should do the same for our models.

Bill

Will Hinton · « **Reply #10 on:** July 22, 2012, 03:52:48 PM »

The Z-poxy method is head and shoulders above all the others. I even use it on musical instruments as well as my planes. Fills great, can be done really light if wiped off as BH does.

Walter Hicks · « **Reply #11 on:** July 22, 2012, 10:10:33 PM »

Guys , the Z poxy seals the surface so the dope does not get into the wood. This is why you can use Non Tauting
Randolph dope. .2 oz Carbon tissue, then auto base coat ,clear coat etc. Al Rabe is helping me with on line and phone
tutoring for the build. He said that the glass cloth it is too heavy, That is why the .2 oz carbon fiber tissue. My question was answered by Alan Resinger by using the Z Poxy finishing resin it will prevent the dope from getting down into the wood.The only reason for the dope is to apply the carbon tissue. Then all auto paint products including primer that does not shrink per Bob Hunts articles in MA.

Avaiojet · « **Reply #12 on:** July 23, 2012, 08:17:03 AM »

Quote

Then all auto paint products including primer that does not shrink per Bob Hunts articles in MA.

I've been finishing models that way since the 80's. Bob has good articles with great information.

Not to keen on the Z-Poxy though.

Charles

Trostle · « **Reply #13 on:** July 24, 2012, 12:28:52 AM »

Quote from: Avaiojet on July 23, 2012, 08:17:03 AM

(Clip)

Bob has good articles with great information.

Not to keen on the Z-Poxy though.

Charles

Good to know that Bob has good articles with great informtion.

But what is wrong with Z-Poxy? Inquireing minds want to know.

Keith

Avaiojet · « **Reply #14 on:** July 24, 2012, 10:04:56 AM »

Quote from: Trostle on July 24, 2012, 12:28:52 AM

Good to know that Bob has good articles with great informtion.But what is wrong with Z-Poxy? Inquireing minds want to know.Keith

Keith,

Have you ever picked on me for misspelled words?

Yes it's interesting, who would have thunk automotive finishing systems? Becoming the thing for more recent learned individuals.

Someone should have asked me back in the 80's. Could have saved a bunch of time.

The Z-poxy, you wouldn't believe me if I told you. Everyone has said it themselves, I can't build, I can't finish, can't fly, I can't even spell.

Automotive finishing system with no Z-poxy. Actually painted in the late 90's.

Charles

john e. holliday · « **Reply #15 on:** July 24, 2012, 10:38:27 AM »

If you click on a post that you have made, you will see the icon that says remove. Have to do it within a certain time. I know as I have had to remove some of my own posts per requests.

Mark Scarborough · « **Reply #16 on:** July 24, 2012, 10:45:11 AM »

Quote from: Avaiojet on July 24, 2012, 10:04:56 AM

Keith,

Have you ever picked on me for misspelled words?

Yes it's interesting, who would have thunk automotive finishing systems? Becoming the thing for more recent learned individuals.

Someone should have asked me back in the 80's. Could have saved a bunch of time.

The Z-poxy, you wouldn't believe me if I told you. Everyone has said it themselves, I can't build, I can't finish, can't fly, I can't even spell.

Automotive finishing system with no Z-poxy. Actually painted in the late 90's.

Charles

you avoided a legitimate question again Charly,, what is your problem with Zpoxy,,

Trostle · « **Reply #17 on:** July 24, 2012, 11:56:24 AM »

Quote from: Avaiojet on July 24, 2012, 10:04:56 AM

Keith,

Have you ever picked on me for misspelled words?

Yes it's interesting, who would have thunk automotive finishing systems? Becoming the thing for more recent learned individuals.

Someone should have asked me back in the 80's. Could have saved a bunch of time.

The Z-poxy, you wouldn't believe me if I told you. Everyone has said it themselves, I can't build, I can't finish, can't fly, I can't even spell.

Charles

Well, I am certainly pleased I gave you another excuse to post those pitchers agin.

And yes, I have picked on you for misspelled words only becuz you are doing it almost every chance you get. One thing you mite want to consider before you do your spellin critiques on everybody is that there (their) are such a things as typographical errors.

I really do not want to go back to the 80's, so whut is wrong with Z-Poxy? Then, let me be the judge on whether I believe you. Inquiring minds want to know.

Keith

Howard Rush · « **Reply #18 on:** July 26, 2012, 11:30:32 PM »

I gotta try that Z-Poxy. Thanks, folks.

Randy Powell · « **Reply #19 on:** July 27, 2012, 09:20:52 AM »

You crack me up, Keith.

PJ Rowland · « **Reply #20 on:** July 28, 2012, 12:02:42 AM »

There is NOTHING wrong with Zpoxy, I use it under my carbon Veil. I prefer .3 oz instead of the .2 over the wings just to give that extra surface to sand.

Using it in combination with Randys aerofiller its hard to beat for lightness. My last airframe from Bare wood to clear was 7.5 oz.

Walter Hicks · « **Reply #21 on:** July 29, 2012, 09:29:47 AM »

I guess since I started the topic I can ask another question. The two hobby shops near me do not have Z Poxy
products. I have some 20 min. Finish cure by Bob Smith Industries. Is this pretty much the same thing? I am assuming
that it is. (Yes I know what assume means)

Alan Resinger · « **Reply #22 on:** July 29, 2012, 05:31:42 PM »

Walter,
The Z-poxy is specially formulated as a finishing resin. You can get it from Tower Hobby. I wouldn't use the other stuff as it is formulated to use as an adhesive. It will not sand well plus you will get what epoxy experts refer as amine blush on the cured epoxy. It is part of the curing process and deters adheasion of further coats on top. Use Z-poxy and lightly sand with good quality 400 grit dry paper.
Alan

Balsa Butcher · « **Reply #23 on:** July 29, 2012, 06:14:58 PM »

Hi Walter: Re-affirming what Alan said and what you said regarding the word "assume": For your purpose the only product you want to use is "Pacer Z-poxy Finishing Resin". The black and yellow (and green and magenta) box has the manufacturer's code "PT-40". 2 six ounce bottles (resin and hardener) cost around $20.00 but will last for multiple projects. Z-poxy is amazing stuff in that it hardens like epoxy but is easy to sand. I also use it to apply fiberglass over cowls etc. and to bond wing skins to foam cores.

Walter Hicks · « **Reply #24 on:** July 31, 2012, 07:07:12 PM »

Alan and Balsa butcher. Thank you so much for the response. I will order some Z Poxy. I know what it is but our local
Hobby Shop does not carry it. I will get on line and get some on the way. Thank you for sticking to the subject.
I have put way too much work into the Rabe Sea Fury to mess up any future finish. Since it is 100% sheeted it is very
important to keep the finish light and not have the wood buckle and make "waves". I am hoping that the .2 oz
Carbon Fiber and Base Coat Clear coat system will do the trick. The last plane I used the .2 oz Carbon Fiber was Brodak
Dope.

Will Hinton · « **Reply #25 on:** July 31, 2012, 07:53:34 PM »

Actually Walter, the Bob Smith 20 minute Finish-Cure is a finishing resin. BSI makes epoxies for any and all applications. I've used it as well as Z-Poxy and find it pretty much the same except for less of an amber color. The Z-Poxy is a tiny bit thinner than the BSI, but not enough for the BSI to be more unfriendly, it just takes a bit more pressure on the paper towel to get it wiped off. Since I'm using the BSI mainly on hardwoods, that makes no difference for me. For balsa, the "Z" is the best, but not the only.

Bill Little · « **Reply #26 on:** August 01, 2012, 02:56:04 PM »

Quote from: Walter Hicks on July 31, 2012, 07:07:12 PM

(snip)
I am hoping that the .2 oz Carbon Fiber and Base Coat Clear coat system will do the trick.
(snip)

Hi Walter,

The great thing about the basecoat-clearcoat system is the extremely small amount of material that you actually use. The coverage is so great that a minimum of color is needed. I painted my Argus with a total of 5 oz. *MIXED* of basecoat light green. One fairly light coat completely covered the model. I mixed the trim colors an ounce at the time and used an airbrush to spray on the trim. Probably the lightest potential finish using opaque colors!

Bill