Fire Sleeve - Proper Install Info Sought

[FastEddieB]

In my thread about the low fuel pressure indications in my Sky Arrow, I think it was Roger who pointed out that all my fire sleeve was improperly installed:

 

 

As you can see, the factory just slid the fire sleeve over the fuel lines, with no effort to "finish" the ends.

 

I found a great little video from the EAA here: http://www.eaavideo.org/video.aspx?v=44938120001

 

It addresses the need to properly "dip" and secure the ends of the fire sleeve, to avoid contamination of the fireproof material. But they're using hoses with fittings attached, not the simple hose clamp setup my installation uses.

 

It appears I have two options:

 

1) Trim the fire sleeve so as to allow about 3/4" at each end to allow exposed hose with room for the hose clamp, or...

 

2) Just allow the fire sleeve to run up over the existing clamp and cinch down over that.

 

In both cases I would "dip" the end of the fire sleeve before installation and allow it to dry.

 

I'm leaning towards #2. A chain is only as strong as its weakest link, and even a little exposed rubber fuel line would leave the entire run vulnerable to fire at each end.

 

If I go with #2, it also would make sense to just use stainless hose clamps instead of the one-time-use clamps made specifically for fire sleeve. It seems like it would be just as secure, and much easier to remove-reinstall than the other clamps.

 

Finally, I want to use the proper "dip" - the EAA video states that many use high-temp RTV, and that its an option, but its not designed for the purpose and will burn in a flame. But Aircraft Spruce wants $136.95 for a can, though I see Wicks has it for $120. Yikes!

 

I found this site on Google: http://www.americanfiresleeve.com/firesleeve-high-temperature-heat-flame-pyro-resistant-end-wrap-seal-tape-liquid-silicone-rubber-dip-paste-order-now.html. They offer a 16 oz jar for $36.95. Anyone have thoughts on this as an alternative?

 

It also just occurred to me that someone on this site may have some extra lying around - if so, I'd be interested.

 

And I'm curious - how did CT handle the fire sleeve issue?

 

Thanks in advance.

 

edited to add: I found this photo using Google:

 

 

From flightdesign.com. If its accurate, i think I see what they did - they clamped the hose but left enough "extra" to cover the hose clamps. Is that about right?

[Roger Lee]

Hi Eddie,

 

The FD pictures are correct. Get the 16 oz. "End Dip" it goes along ways. I had to buy a whole quart when I bought it. The fire sleeve has to cover all hose so it should go over the ends and then clamp it down. You can use that style of band clamp or an Oetiker one eared band clamp. The other clamps need a special tool. You really should not use screw clamps. Dip each hose in about 1" in depth. let them dry for an hour or so, then slide them back on and clamp. Coolant hoe doesn't need covering, but fuel and oil do.

[FastEddieB]

Thanks again, Roger (we can't go on meeting like this!)

 

What's the reason for not using hose clamps (other than they're ugly!)

 

I had never heard of Oetiker clamps but I found their website and they look good. Is that what you use?

[Roger Lee]

Hi Eddie,

 

You can call me anytime and get all these questions handled in one call. You should be using a band clamp and an Oetiker clamp is just one style of band clamp. You should be using band clamps on your fuel and oil lines, too. Screw clamps are okay for coolant lines. The Oetiker one ear band clamps are easy to use and easy to get off. The other stainless clamps you see on the FD fire sleeve take a special tool to ratchet them down. Seem's like I spent somewhere from $60-$80 for mine. I would buy my Oetiker clamps and clamp pliers from Chads Toolbox on line. Much cheaper than some places. You may want to buy the kit up front then pick up a few extra clamps for the particular hose you have.

 

 

Nice picture. A Flight Design with a Rotax 914 turbo.

[Runtoeat]

FastEddieB, I just happened to watch the Rotax video regarding fire sleeves yesterday. They advise to not leave any exposed rubber hoses and also say don't use screw clamps but use the flat Oetiker clamps. No surprise that Roger's advice agrees with Rotax. I've seen a lot of fire sleeves installed wrong based on the video and Roger's advice.

 

The only thing I don't like about the Oetiker clamps is that I don't think one can go back and "tweak" them to tighten if one has a "weeper" or a slight drip. I normally need to tweak the screw clamps on my water lines occasionally since they seem to relax and develop small leaks. After new hoses are installed with Oetiker clamps, I would imagine that these will keep relaxing for a few years and I do not think that these allow one to tighten them. Believe that one must install new clamps each time a leak develops. Roger indicates that we might get by using screw clamps on the water lines. This may be the way to go here. This hose replacement may cause more trouble than what it's worth. I know that the hoses deteriorate over time so I'm just venting here and realize that the change is needed.

[Roger Lee]

Hi Eddie and Dick,

 

You do use the screw clamps on coolant hose for two reasons. One the rubber will compress over time and and the large diameter hose over metal tubing tends to expand and contract more than some other applications like fuel. That's why Rotax and other engine Mfgs .use the constant compression clamps (self adjusting so to speak) and the screw clamps that you can go back and tighten. I have tightened every single screw clamp on every aircraft on the coolant side during an inspection. They tend to be loose the first inspection and by the third they usually won't tighten any more.

The fuel and oil are not supposed to have screw clamps. Screw clamps can fail if over tightened trying to secure a hose well, but a band clamp should be more or less semi permanent and won't fail when you compress it. The Oetiker's won't leak or need tightening if you use the right size. If they did all the CT's would be leaking by now not to mention all the other aircraft that use them. The clamps on the fire sleeve itself do not have to be super tight just snugged down well. We are only trying to protect the rubber parts from fire and should cover the oil or fuel hose all the way over the fitting so no rubber is exposed..

The fire sleeve can have two different types of band clamps. The Oetiker band clamp or the Band-It band clamp. The Oetiker meets the standards and is much easier to apply.

 

 

p.s.

For the CT owners that always seem to add a tiny bit of water in the over flow tank or your tanks seems to drop it's level over a few months then just go and tighten the screw clamps on the coolant lines. Even though you can't see ant coolant dripping it is under pressure and with the heating and cooling it gets blown off and dried by the air flow under the cowl.

[Roger Lee]

Here is a picture of the Band-It clamp appliance that I use. Actually I try never to use it and use one eared Oetiker band clamps most every where.

 

http://www.aircrafts...uipClamping.php

 

 

Here is a picture of a Band-It clamp

 

http://www.dultmeier.com/products/0.630.631/1744

 

 

Here are some pictures of Oetiker band clamps

 

http://www.oetiker.com/content.asp?l=4&idNavig=17

[FastEddieB]

Just as an update/followup/warning...

 

Be cautious about dealing with these guys:

 

http://www.firesleeveandtape.com

 

I placed my order for end dip, clamps and tool back on Mar 9 and still don't have them.

 

Communication has been spotty. They finally said the tool was back-ordered and should be arriving shortly. They didn't mention any option to ship the part of the order they could now and the tool later, or any other recourse. If I had everything but the tool, I could borrow a tool from one of my homebuilder friends and get the job done.

 

If the order doesn't ship by Monday, I'm probably going to cancel and look for another source. They were the best price on a reasonable amount of the end dip.

 

If I get the clamps and tools elsewhere, are either fire sleeve tape or hi-temp RTV viable options? One of the rather meticulous RV builders said the RTV was just fine and others have suggested the tape.

 

I know any of the options would probably be fine under most foreseeable circumstances, but I'd really like to do this right, as long as I'm doing it at all.

[Roger Lee]

Hi Eddie,

 

If you not in a hurry End Dip is what is recommended. I have seen few few people use RTV, but maybe the least of the choices and not very nice looking. It's more slopy and hard to deal with when you want to take things apart. I have not used the tape, but from what I can see it looks like a nice option and does a good job around the ends. This may be a good way to go if you don't use the End Dip. You could have used an Oetiker clamp on the ends of the hose and fire sleeve.

[FastEddieB]

I finally cancelled my order with those guys - again, NOT recommended as a source.

 

I still need enough fire sleeve "end dip" to seal the ends of about 5 or 6 hoses. Before I order a can of the "good stuff" for $136 (!) from Aircraft Spruce, does anyone have extra just laying around who might want to recoup some of their expense? Or maybe go 50/50 on a can from Aircraft Spruce (I think its a quart)?

 

Let me know at FastEddieB@mac.com - thanks!