Scat Tube

[Rjfanjet]

Quick question. I have a 68C and replaced the scat tubes to the windshield defroster recently, original from what I can tell. Anybody know the diameter of the scat tube from the NACA duct intake to the air mixer? I didn’t want to take off the original and measure, looked like it was going to turn to dust as soon as I touched it and I have a few flights scheduled this week. 
 

Thanks!

[jetdriven]

I just measured this K model here in my shop, and it looks like 2 1/2. 

[carusoam]

The original tubes, spring wire, will crumble in your hands...

Getting new tubes all the way around makes a great project, prior to winter....  

Best regards,

-a-

[Rjfanjet]

Thanks! Winter is almost here in Utah!

[PT20J]

Courtesy of Wicks Aircraft:

CAT – 1 ply neoprene impregnated fiberglass with very closely spaced spiral copper coated high carbon steel wire inside exterior wrapped fiberglass cord. From -85 degrees F to over 350 degrees F. Aircraft type. Maximum length 10 feet. (BLACK).
SCAT – 1 ply same as CAT except with silicone rubber impregnation. From -80 degrees F to over 450 degrees F. Aircraft and industrial type. Maximum length 11 feet. (RED).
CEET – 2 ply neoprene impregnated fiberglass same as CAT except wire between plies. From -85 degrees F to over 350 degrees F. Aircraft type. Maximum length 10 feet. (BLACK).
SCEET – 2 ply same as SCAT except wire between plies. From -80 degrees F to over 500 degrees F. Aircraft and industrial type. Maximum length 11 feet. (RED).

Attached Aeroduct catalog has everything you want to know about ducting.

In the engine compartment, I use SCEET. SCAT is more flexible, but the wire always seems to eventually work it's way through the thin wall no mater how you terminate it. In the cabin, CAT works well and is very flexible. 

Guy @GEE-BEE can make you ducts in whatever length and diameter you want with professionally finished ends. They will last to at least TBO. 

Skip

AERODUCT-Aviation-Ducting-and-Hose-Products-Catalog.pdf

[cctsurf]

21 hours ago, Rjfanjet said:

Anybody know the diameter of the scat tube from the NACA duct intake to the air mixer?

I just replaced this on my '62 c model and it was 2 1/2".  I replaced it with CEET, because it will hopefully last longer...but if yours is original, it lasted pretty long.  I doubt mine was, but it was difficult to measure because it did turn to dust as soon as I attempted to remove it.

Installation was not easy, there were a number of wires that were pushed up against it that made it difficult.  I actually posted to here asking if I had the wrong size duct because it was SO difficult to get on...  I bent the intake end to fit and then with that end off, turned it onto the outlet end until it was sufficiently on the air distribution box and the other end was clocked correctly.

Hope that helps.

[Rjfanjet]

Old and new. Nice 4 hour project.

[carusoam]

Fancy, Like brand new!

-a-