Killer_Matt

My Feedback: (11)

I have a new Bisson muffler on my GT-80 with smoke fittings. These fittings are rather large and seem to fit fuel line in the 5/32 dia. size, my issue is I tried Tygon yellow gas tubing and it just melts. I think I want neoprene but can't seem to locate something in a 5/32 id dia. The normal neoprene medium from Hayes and the medium from Du-Bro look to be to small and I'm assuming they will just split.
Any Ideas?

Thanks

RCAddiction

My Feedback: (87)

Lube the smoke fitting with a bit of the oil you mix with the gas. The neoprene expands quite a bit more than one might think and I've never had the Hayes tubing split.

Sometimes it helps if you cut the tip of the neoprene tubing at a slight angle to help it slide on more easily.

Killer_Matt

My Feedback: (11)

Thanks for the suggestion. I will certainly keep this in mind and may use it.

I did however find this product by Sullivan and plan to give it a try.

Smoke Oil Tubing 5/32" ID 3 ft
Description: Special black "Buna-N" tubing is resistant to smoke oils and heat, making it ideal for smoke applications. Has an oversize ID for easy fluid flow.

http://www.shopatron.com/product/par....329.339.0.0.0

RCAddiction

My Feedback: (87)

That's a good find.

jack1933

My Feedback: (2)

Hello all, I have used silacone fuel line with sucess, glo fuel tubing. Does not melt, and the smoke liquid has not attacked it.

Killer_Matt

My Feedback: (11)

Glow fuel line.... Now why didn't I think of that, I guess I had gas on my mind. Sounds like the way to go.

Thanks

RCAddiction

My Feedback: (87)

Guys, if silicone line was impervious to smoke oil, then why do all of the manufacturers produce gas/smoke fuel stoppers, fuel line, etc rather than mention cheap, easy to get silicone?

It depends on what you are using for smoke oil. If you are using MDW SuperDri, which seems to be the most popular smoke oil out there, I suggest you go to their website. Here is what they recommend:

Tubing for gasoline and smoke oil must be impervious to petroleum-based products and must withstand the high heat at the muffler attachments. Our experience has led us to use both black neoprene or "primer� line and Tygon (yellow) tubing, 1/8� I.D. The black “primer� line is less-costly than Tygon. But, the Tygon line will not withstand the high temperatures found at the exhaust connections. Therefore, we use Tygon for all gas and smoke oil links with two exceptions: (1) the lines connecting smoke oil directly to the exhaust fittings, and (2) vent lines from both tanks to aircraft exteriors. We have also learned to not use the black “primer� line inside gas and smoke oil tanks. Over time, the black line will degrade in the gasoline and will cause a buildup of “gunk� in the carb filter screen, a maintenance task you do not need.

Note: Silicone tubing is not resistant to petroleum based products.

Bob Pastorello

My Feedback: (198)

If you intend to use smoke systems for a long time, on various airplanes, different sizes of gassers, etc.... it could be worth it to invest in 1/8" I.D. "VITON". Pretty expensive.... but I have never had to replace the short piece that goes from the final check valve to the injector nipple. I try to leave that piece about 3" or so....McMaster Carr sells the stuff. It is impervious to almost anything you'll pump through it for smoke oil, and doesn't get affected by the heat nearly at all.

Just another suggestion to throw into the thread.

As always, MANY ways to do all of the things we do....

RCAddiction

My Feedback: (87)

That's actually what I use, Bob. Most people get shy about spending the money, or buying anything that doesn't come prepackaged at the hobby store.

I just finished plumbing a gas tank for my DA-85 1/2 hr ago with a low durometer Viton clunk line.....from McMaster, with a Walbro felt clunk.

Bob Pastorello

My Feedback: (198)

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ajcoholic

My Feedback: (10)

posted this previously but for some reason it didnt show up...

A simple "fix" I have used many times is to silver braze a short (maybe 2" ) section of K&S brass tubing of whatever size you wish to use, to the brass fitting. Then you can use tygon (readily available) without issue. The length of tubing radiates enough heat that the end of the tube where the tygon goes on stays well below temps that will melt the tygon.

I use a real silver wire for brazing, but I think a low temp silver solder might withstand the heat... but brazing is 100%.

Takes but a few minutes and you will never have to worry about melted tubing again!

AJC

Bob Pastorello

My Feedback: (198)

Andrew - that's a pretty dang good idea!
Thanks!