Carl Goldberg Shoestring

Thank you Levent for your recommendations. Actually the wing covering, presumably Monokote, is actually pretty good with teh exception of a small spot on the underside of the wing on the sheeting beside the fuselage. I just went and played with the engine a bit. After removal and some heat from the heat gun, it is now freed up and seems to have a nice 'pop' to it. Also while looking it over, I am starting to possibly think that the paint is actually good and not flaking, but the paint, or whatever was used, had sank into the woodgrain. I will have to investigate a bit further. as I now have the tail clamped and glued as the elevator halves have seperated from eachother. Not broken, but rather a 2 piece elevator and the joing had simply let go. From there I will have to grab a couple of pins and install them in the hinges, find a needle and well, wait till spring to give it a run, and possibly flight!

I like the look as it is. It certainly has vintage appeal and I would personally preserve it by maybe applying a coat of clear polyurethane to seal it and leave it at that.

Thanks guys. As much as I would like to redo the model to its former glory, I just don't think I can do the job I would want or even anywhere near the quality of work that someone like Bob would do I do think I will leave it as is. Then as per suggestions, clear it and well, fly it. However, flying will definitely not get done till next year, but clear may get done this year yet. Bonus is that it will have a long time to dry properly.

Now to just find a needle for it, preferably used. With that said, however, I see there are 2 types made. Straight taper, and a straight taper with a flat on it..... Just enough to make one do some research.... Will definitely update as I go along.

Yes leave it as , I would consider an overcoat of sealant . Very nice and I hope you can get some outside fun in sooooon !!!

If Kim doesn’t find a needle I probably have one.

If you do fly it. Do a pull test first. Glue sitting for 45yrs becomes brittle. Also the Fox likes to shake. If those doublers weren’t epoxied on they will definitely separate from the fuselage.

Cool plane!

The color appears to me to be Aero Gloss Curtis Blue. Nothing really top coats it well. While polyurethane will work it adds a lot of weight. There's so many things that can be wrong with old planes like this. To add to the issue, the Shoestring has a design flaw within it. The two center ribs spaced apart under the sheeting creates all kinds of harmonics in the nose making it act like a tuning fork. The solution was to make a solid rib during construction. Having a Fox on the nose can certainly make it worse and on a old plane it will shake the hell out of it.  This means that you can't acquire a needle setting because it will foam the fuel and have the engine run all over the place.

         This of course might not happen but when it does, the plane is done. When cellulose based cements were used which this plane may have been constructed with speeds the destruction  process up in seconds. Opening the wing  covering can reveal this and most if not all glue joints with Ambroid is separated.

        As Ron mentioned, a pull test is important and I will pull on the hinges as well as they can fall out equally. Most important, DON'T RUN that prop. They can and will explode. Boiling it doesn't fix it, throw it out. I can tell you first hand as my flying partner had one goes through the side of his face and I had one go through my rib cage almost hitting my lung.

          I wonder why the main feature of the plane, the cowl was eliminated.

Thank you all for the help and tips. I will do a pull test to see what happens first, and also I will check the tail hinges as well, just because it is easy. I will take a peek to see if I can determine if the doublers were epoxied on, but not sure exactly how this can verified if I cannot see any residue from epoxy. All I also know is that the gentleman that had built it said that he used to fly the begeesus out of it and did a lot of stunting with it. The elevator throw is quite large. And as for the cowl being omitted, I am not sure why. I had only figured this part out last night when I was looking around online at other builds. No obvious marks either showing that it was ever installed. While I would love to add one, I will not as I want to keep it as it is.

Hi New222, awesome find. Glad you picked it up. I seen the posting on kijiji or Facebook marketplace can't remember lol. I was thinking 14day road trip excuse

Can't wait to see some flight reports.

I like the color scheme.

Ok. So just a tiny update for today. I looked teh front end over and seems to be very solid and good to go. I went through the elevator hinges and made 3 pins for the ones that were missing to join them as they are pinned hinges. Did a pull test on the elevators after and were all solid and no movement. I then sat down and masked off the fillet around the wing and proceeded to make a new thin fillet of epoxy around it on both sides as I just wanted to make sure that it was securly mounted and now seemed to be the better time to do so. If all goes well tomorrow afternoon, and the weather does cooperate, I do plan on giving the plane a light coat of polyurethane to preserve it as it is. Then comes the next part of flying, but that will have to wait till spring more than likely as our control line club is winding down for the year I think. And also to be safe, I will probably have an experienced member take it up for the first flight too just to make sure everything is good. And lastly is to try and find a tank suitable for it. Would like to try and get a period correct tank if possible. I have a coupel here somewhere, but have a feeling they are going to be either too big or too small.

Off to do some reading of what size fuel tank is recommended for a Fox 35 for approximately 3 - 5 minutes.

Well, I just sprayed on a coat of Minwax polyurethane clear about a half hour ago, and now waiting for it to dry. Will be interesting to see how much weight it will gain. Will post again later when it is dry and I weigh it. Depennding on how it looks, I just may spray a second coat for extra protection.

Any chance the fox needle is the same as the old McCoy's? Could gently test with a 2-56 push rod or fastener. I have been able to turn those into very well functioning replacement needles for McCoy's.

Nice job getting the clear sprayed on.

Here's one example;

Thanks roddie for the kind words. It truly is a cool looking airplane. I vaguley recall that the shoestring was a plane I remember wanting when I started in control line back in the day, circa 2000. Never had or got one then, but patience has paid off. However, I am now ever so slightly bummed about it not having the 'cheek cowl' on the inboard side, but I can and will live without it. Especially since I have just cleared it. But this was more about preserving the model the way it was built those many years ago rather than remaking it into what I had wanted.

layback209 wrote:Any chance the fox needle is the same as the old McCoy's?

If they are the same thread, the McCoy needles are still readily available new.

@layback. I do not believe that it is the same as I had used a short screw I had here from someone that threaded into the spraybar nicely and snugly that is 3-48 tpi. Looking around online the Fox needle was said to be 3-48 tpi, so believe that is what I will need. I have thought about recreating a needle as you have pictured (but would not be able to do as nice a job as you), but will leave that as a last resort if the other lead does not have what I need. I have a broken needle assembly here from some parts I had sometime acquired in the past that I had tried, but it too is not correct. Just came across it in my 'screw bin' so thought why not try. No bueno!

I shall also admit, I am a a bit worried about how this plane will move along the circle as it is signifigantly smaller and lighter than a Twister airframe I have here that weighs a lot more than this, and I have seen the Twister and Banshee planes fly quite well with the same engine strapped on. Hopefully this thing will not be a speed demon, but rather a Ringmaster sort of fun flying airplane.....

NEW222 wrote:@layback. I do not believe that it is the same as I had used a short screw I had here from someone that threaded into the spraybar nicely and snugly that is 3-48 tpi. Looking around online the Fox needle was said to be 3-48 tpi, so believe that is what I will need. I have thought about recreating a needle as you have pictured (but would not be able to do as nice a job as you), but will leave that as a last resort if the other lead does not have what I need. I have a broken needle assembly here from some parts I had sometime acquired in the past that I had tried, but it too is not correct. Just came across it in my 'screw bin' so thought why not try. No bueno!

Bummer it's never simple. That's interesting about the size would have a bit more meat to it. Probably I good thing. If you do find yourself in a bind I can spin one for you (not sure I have the screw size though, hobby shop Probably does). I think I could ship it for like 1 $ in standard letter mail. People used to send photos lol. We gotta save those nitros. I've also heard that the Enya spray bar and needle is interchangable with these, but don't take my word for it. If you have one you could try it?

Forgot to also thank you roddie for sharing the 1/2a Shoestring plans. A cute little model. Not that I need another at this time, but one day you just never know.....

Don’t worry about the .35 and the Shoestring. It won’t be overwhelming. Keep the throws around 15-20 degrees either with the handle or the horn. APC 10x5 is the prop I would recommend.

.35 Fox engines were the standard when that plane was designed. It’s like peas and carrots.

Be patient about the needle, either Kim or I will set you up. Worst case … or better case you can always use an ST needle which is superior to the standard Fox anyway.

Last little update here for a bit as things will be allowed to dry very thuroughly. Clear did about as I had expected. Just from the scale as it sits ready to fly minus a fuel tank and needle, it weighs in at 1 lb 11.1 ounces. So as I was worried earlier, I am thinking that this thing will definitely haul the mail! This is also with the original propeller which will be changed out however to fly.

Lastly, with that said, should I think out some epoxy and brush it in the engine mounting area, or will 2 coats of aerosol polyurethane be good? Again, the extra weight should not amount to that much. Thanks.

Thanks Ron. I do have a problem however with the throws that you mention as well, the elevator deflects approximately 45 degrees each direction as built. He did tell me that it did loop and turn very well and quickly...... Back to panic mode again!

I have a bunch of Master Airscrew 10 x 6 props here, but no APC, nor are they locally available anymore with one of our two hobby shops closed down. Hopefully that will work. Now I'm thinking I may actually have a 10 x something APC propeller from my old Fox 35 I got rid of/traded a couple years ago when I was gonna convert my Twister to an RC ship as per advice from my friend.... Never happened. But may be the better test bed now. Gonna do some digging tomorrow for it and a possible tank.