Jim Walker Bonanza etc.

rsv1cox wrote:Robert, I have no idea how you can take those colored pieces of tissue and apply them so accurately and without tearing.  Amazing. An airbrush could not do as well.  

Uh huh... yea.. what he said..

CEF member DanMc (Dan McEntee) sent me a sample of what he referred to as Doctor's Paper; a disposable paper that covers examination-tables and tears-off a roll..) which he was experimenting with. Not sure whether it is shrinkable for open-frame construction.. but I'm curious now; if it could be used (painted/tinted) to make trim like Robert has.



Its' thickness is .002" but I have not tried to use any yet

I had a doctor's appointment this past week.. and saw a box of rolls under the table and thought.... ....  

Thanks Bob, Roddie ….. There was a time when raising a young family about all I could justify on modeling was rubber powered  free flight….. Learned a lot about tissue work during that time ….. I still have a pretty good supply of Esaki tissue, it’s  strong and holds its color well…. When I started flying gas again I just used what I had on hand….. Only regret is I’m running out of Sig Lite Coat dope which was my go to for working with tissue…. I ordered a few Sig Super Coat bottles while it was still available but I know it will shrink a lot more…. When I get ready to try it I’ll add some castor oil for retarder and test it on some thin balsa and maybe some open frames covered in tissue….. Thoughts from dope users?….Maybe it won’t be an issue if I stick with sheet surfaces…

I’ve read about people using that Doc paper Roddie…. I’ve taken a swatch or two from Dr visits…. Seems like it might be an OK substitute for light silk span…. If you decide to try it let us know how it works out….

Gentlemen,

Dan Mc turned me onto this stuff several years back. I began calling it DocSpan as the more common name is a mouthful! I've used it on my models since sometimes around 2018 or so. I discovered it has good shrink-rate, but with no real bias. I believe that lends to it swagging between ribs as it pulls front to back as well as side to side. It takes dope and clear sanding lacquer fabulously. My next plane will have stringers across the leading edge and the paper installed close to bone dry to minimize the swag. Look for my Brown-Novotnik Mosquito. You can see the swag in that deep rib set. The paper was damp. It shrank. It swagged. I doped again and hit it with a hair dryer, which promptly put the outboard "flap" in the raised position. I hope to "use the raised flap" to offset the line weight. Yeah...that sounds like a good reason for the "flip tip."

The typical stuff I find in medical offices near me is the shiny-on-both-sides more crinkly stuff. Beware if you grab a few feet from your doctor's office. What you want is "every day crepe exam table paper," sold by Tidi (or McKesson), part number 98-1002 (18" wide) or 98-1004 (21" wide). I think McKesson uses different leading digits, but the last four are the same. It is commonly found in 125 foot rolls, but 250 foot rolls may be available. The real clue is the "every day crepe."

I got mine several years back as a single roll for about $13 delivered. I have not found a single roll source since. A broken box appeared on eBay many moons ago for practically peanuts.

The "Doc " paper was introduced on Stunt Hangar many years ago and I decided to try it on a 42" plane. My experience with it was not positive. I found it to not shrink like silkspan and even using Supercoat, it wasn't pulling out the wrinkles in the compound curves. It was removed and never used again. Polyspan works better aside from the fact it takes a fair amount of dope to obtain a good finish. Polyspan also doesn't have 1000 numbers attached to it. You order the Polyspan and you get what you ordered.

Polyspan will heat shrink prior to doping therefore the need to use a lot of taughtening dope is not required and is better for the longevity of the model. Especially for those using it on 1/2A's. I for one don't know why one would do that as I learned very early on that using silkspan covered models on 1/2A's is a total waste of time unless you want to repair the model everytime out. Using iron on covering is not heavier than a silkspan finish on a 1/2A.

As far as Lite Coat availability, I don't think were ever going to see Sig dope return. I was bs'd by Sig for 2 years telling me everytime I called that it would be in stock approx 2 weeks. Randolph offers non taughtening butyrate which is essentially Lite Coat. In addition, I don't like adding castor oil to dope. I know its what was done years back but it doesn't mix well and it can also cause fisheye issues not too mention lack of adhesion issues. Dave Brown Flex All is a terrific product which makes the final coats very supple and flexible. It can be hard to source but once you have it, a bottle will last forever. Adding it to Supercoat will essentially stop the shrinkage and plasticize it.

Thanks Ken for mentioning those products…. Will look into them and try and source!!… Perfect

The Doc paper would be fine on sheeting, open bays receives a big thumbs down from myself. The big problem I see with Sig products is that thinner is not available. This is essentially what makes Sig dope so good. The slower thinner offers a nicer shine, longer workability and no brush strokes when brushed. I was using Dupont 3608 S for years but it's not a substitute for the same workability Sig thinner offers. It was a fairly fast evaporative thinner but it was compatible with Brodak as well. The nice thing was I was purchasing the gallon for $24. The Dupont paint line is now Chromax and the 3608S is still available. It's no longer $24. Chromax offers 3602-S which I believe is similar to Sig.

The problem with these items is that purchasing them becomes difficult. The reality is they don't even want modelers spraying or brushing high voc paints and to obtain some of these products one needs to be in the business. My neighbor owns a body shop and even for him from his PPG paint line, the equivalent thinner I would require from PPG is $80 a gallon even at his cost. This is what makes buying direct from Randolph very easy. When I order from Randolph, it's essentially at my door the following day. Amazing service they have in regards to getting their product out the door.

Nice! If it were me..... I'd do the elevator/linkage the way that Wen Mac did it.

I have lots of old silk-span... really old.... Stuff that was in the Veco, Sterling, Goldberg and Top Flite kit-boxes that my Uncle gave me 30 years ago.. and they were probably 30 years old when he gave them to me. Many of those boxes had the unused silk-span, balsa and plywood scraps, glue-dotted plan-sheets, unused music-wire nose-gear, "Bear" sandpaper.. Celluloid sheets.. double-edge razor-blades.. empty dried-up glue-tubes.. memories. A couple of those boxes haven't been opened in 25+ years.

There's some T-style horns you could use for that elevator.. and WOW... lots of nice goodies within view in that box!!! Saito 4-stroke.. O.S. engine box (?) Hobbico/Torque Master elec. starter.. and that's just what's in-view..

Hi Bob, I scanned OZ Bonanza CL plans to see if there was a better trick to hooking up that V-tail (both elevators used)…. Looks like about the same as on your JW plan detail…. Kind of weird geometry for a single shaft passing thru two horns but should be OK with good alignment….

Just a thought on that V-tail elev. link... Rusty K. (God rest his soul) had a "Yak" control-line model that he used a "lucky box" (??) type design to connect the flaps.









Here's the THREAD..

I keep scratching my head regarding JW's V-tail elevator linkage.. and decided to search the web for ideas. A Stunthangar link came up, which has some interesting solutions/recommendations.

Stunthangar link

I like the "dual-pushrod" idea.. but not sure how that would work-out with a profile fuse. I suppose you'd need to "slot" the fuse for the outer-elevator's pushrod to pass through.

Walt Musciano on his Scientific Navy Cutlass: https://outerzone.co.uk/plan_details.asp?ID=3558 had only one elevon, the left one controlled by the bellcrank. The right one was fixed.


Outerzone plan thumbnail.

If your only intention is 'round & 'round without stunts, that could be a simplistic possibility.

Other option is to make flaperoos on the wing for control and fix the stabilizer.

I am sorry but I think the fuse A Lodge looks funky/strange the way it put together for the engine mount , But other than that its coming right a long  just me being me