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Building Tips and technical articles. => Paint and finishing => Topic started by: Dave Moritz on June 21, 2025, 12:26:04 PM
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Any suggestions or cautions? It’s a Pinto / Norvel Big Mig combo with silkspan. Nitrate underneath and butyrate top coat now. Need to fly it before making it pretty.
Thanks.
Dave Mo…
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I think Jack Sheeks used to fly all his models while in clear in case he had to cut back into the model for any reason. I would say just make sure all cracks are filled, nothing for fuel or exhaust to creep into, and keep the flights to a minimum. They as soon as you finish the last test flight, start cleaning with soap and water!!. Maybe alternate that with Prepsol or similar product. Then when finished, CLEAN IT Again!! Good luck with it!
Type at you later,
Dan McEntee
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Alcohol-based stove fuel from the hardware store works nice for cleaning off castor goo, and doesn't attack dope. I get the stuff that's 50/50 ethanol/methanol; I use it for deep cleaning models & thinning epoxy.
99% isopropyl alcohol from the drug store works, too, but it's way more expensive.
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Thanks, Dan and Tim. Yes,I need to verify fuel tank size aganst run tme. Might need to reconstruct front end for larger tank.
Will mix denatured with methanol for a cleaner.
Dave…
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Let us know the results after testing. I'm flying a Norvel .061 on the middle size Netziband 1/2A Doodlebug. I think I ended up with a 1 3/4 ounce tank but will have to check. I had a thread about this over on the 1/2A section. I'm running 10 and 15% fuel, and the APC 5.5 X 2.5 prop that many recommended. It's a large airplane for 1cc and not really light but this combo gives me plenty of power. Longish lines us
Ing Spectra 15 pound line, just can't remember how long exactly, but approaching 50 ft.
Type at you later,
Dan McEntee
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If you have denatured on hand I'd suggest you use that, and don't mess with mixing it. As near as I can tell, 99% isopropyl is about as good as the stove fuel I use at removing castor oil residue -- I just use the stove fuel because it's cheaper.
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on 1.5 oz of 10% on an oversized Shark 15 my KC .061 runs for 8 min ,06 sec H^^ with a 5.5-2 APC
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on 1.5 oz of 10% on an oversized Shark 15 my KC .061 runs for 8 min ,06 sec H^^ with a 5.5-2 APC
Hey RAD!! Over sized Skark .15 or undersized . If it's reduced, what wingspan? I think I reduced the plans at one time but have to dig them out.
Type at you later,
Dan McEntee
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Gents
Will do, Tim!
The little uniflow tank I made to fit the Pinto space carries just under an ounce. Seems skimpy to me, thus my intent to fly before finishing the model. I too anticipate 50-feet lines of 20# Spectra for test flight. The 061 Big Mig can turn the 5x3 prop at 20K on 15%. Yikes!
Dave Mo…
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Gents
Will do, Tim!
The little uniflow tank I made to fit the Pinto space carries just under an ounce. Seems skimpy to me, thus my intent to fly before finishing the model. I too anticipate 50-feet lines of 20# Spectra for test flight. The 061 Big Mig can turn the 5x3 prop at 20K on 15%. Yikes!
Dave Mo…
Plumb up your tank so it will be able to run on standard venting and uniflow. , with and without pressure, just to make it easy for you to switch around while you are testing. On the Doodle Bug Brothers model I have a .061 on, it had worked best running on standard venting with no pressure, so far. Model size, weight and how draggy it is will dictate how you run the engine. While I was researching mine, some guys said to run them balls out and high RPM and at that setting it won't use a lot of fuel and some said less that an ounce, around 3/4 ounce I think. I'm on really long lines on this airplane, and the engine seems happiest with the APC 5.5-2.5 but lap time are too fast when it's at full lean, so I have dialed it back to the 18,000 range , if I'm remembering correctly. Yours is a full fuselage model, so depending ion what it weighs, it will be a different animal and you may need to run that high RPM mode. Head gasket count, and even different types of glow plugs will affect the run. I'm back with the standard Norvel/NV button head/glow plug, but got one of the Kamteknic heads for Nelson style plugs to try and even tried Cix glow heads, which fit fine and would work well if you needed or wanted to lower compression. There is a lot you can do with these engines, you just have to run them like they like to be run, and not even try to run it like an OS or other "typical" C/L engine. They do not like a lot of prop load and a Cox product engine has more torque and will pull more prop than the Norvel .061, but won't run the same RPM. The three bladed props like were used on a lot of Cox plastic RTF models are useless on a Norvel!! It's been fun and interesting working with these things to see what they like and don't like and I'm just starting to get them figured out, I think!!
Keep us posted on progress,
Dan McEntee
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Gents
Will do, Tim!
The little uniflow tank I made to fit the Pinto space carries just under an ounce. Seems skimpy to me, thus my intent to fly before finishing the model. I too anticipate 50-feet lines of 20# Spectra for test flight. The 061 Big Mig can turn the 5x3 prop at 20K on 15%. Yikes!
I very much doubt that 1 ounce is enough, depending on which venturi you are running. Still, I would be tempted to figure out the fuel consumption some other way that test flying it in an unfinished airplane. - Like, throw together a profile and test it on that.
Brett
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Any suggestions or cautions? It’s a Pinto / Norvel Big Mig combo with silkspan. Nitrate underneath and butyrate top coat now. Need to fly it before making it pretty.
Thanks.
Dave Mo…
Usually the model is painted before you fly it. Good luck getting any paint to stick if you do go ahead with flying it before finishing it.
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Just another reason to fly electric. I had a weak motor mount and the motor decided it didn't like it. Better when it was in primer then when it was finished.
ken
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Paint? Who needs paint?
(https://stunthanger.com/smf/index.php?action=dlattach;topic=38062.0;attach=356227;image)