Boots for firewall piercings?

[Marty_d]

Hi all,

After some advice.

My CH701 has rods from the rudder pedals through the firewall to the noseleg for steering. These rods go through vertical slots as they need to move up and down as the noseleg suspension moves.

I bought a piece of silicone sheet online, but at 2mm it's too thick to deform enough to make into a boot that can move around in the middle while fixed (sandwiched between aluminium collar and firewall and riveted) at the edges.

Has anyone found a solution to this? I'm thinking something preformed, like the Dektite flexible fittings you can get for roof piercings. But lighter and smaller of course.

The slots are 20mm wide X 100 tall.

Thanks, Marty

 

[onetrack]

Here's one blokes solution, Marty (link below). The three biggest problem that I see for your requirement, in trying to find a commercially-made boot, are;

 

1. It seems that all boots are designed to fit round or square holes. I have yet to find a boot that fits a slot, and which allows substantial movement in a straight line.

 

2. There are grommets, and there are boots. Many grommets offer a wide range of shapes, but they're not designed to allow a substantial range of movement, as boots are designed to do.

 

3. You really need the material to be fire resistant. As a result, silicone would be the best choice, it's very heat and fire resistant (450°C), and self extinguishes once the flame source is removed.

 

I think this bloke has produced a workable solution, even if it's not professional-looking. I wouldn't trust those PVC or nylon cable ties, though, I'd be looking at something more durable.

 

https://www.kitplanes.com/diy-firewall-boots/

 

[Marty_d]

Hi OT, 

Yes - saw that one. That's a backup plan, it'd be good to do the out of silicone though (less messy!)

[Kiwi]

Not fire proof,  but should keep the cold and fumes out.

[Marty_d]

30 minutes ago, Kiwi said:

Not fire proof,  but should keep the cold and fumes out.

Thanks, that's the kind of shape I want, but in lighter silicone.

[skippydiesel]

Have you considered wool felt.

 

It comes in diffrent grades, thickness, fire resistant, durable and cost effective.

 

I have home made felt witches hats, as draft excluders, on my aileron /wing root holes - work a treat.😈

[Thruster88]

Perhaps  a fire blanket or one of these welding blankets could be used, make a form out of wood, fit blanket material around form and join the seam with high temp silicone.

 

https://www.vevor.com.au/welding-blanket-c_10056/vevor-carbon-felt-welding-blankets-2-pack-508mm-x-914mm-flame-retardant-welding-blanket-up-to-1800-f-heat-resistant-safety-protection-blanket-3-5mm-thickened-carbon-fiber-fireproof-insulation-mat-p_010421956361?adp=gmc&utm_source=google&utm_medium=cpc&utm_id=21271593978&ad_group=163180832818&ad_id=699136035035&utm_term=&gad_source=1&gad_campaignid=21271593978&gbraid=0AAAAACYOjau14XBmePs9-F5M-n41S3zEd&gclid=Cj0KCQjwoMXQBhDcARIsAH-eEtvXRPrzkvdVRBWQb84ev-zKWuCVrAUwmIbJnrIkFM4d51QVjle-klcaApICEALw_wcB

[Marty_d]

4 hours ago, skippydiesel said:

Have you considered wool felt.

 

It comes in diffrent grades, thickness, fire resistant, durable and cost effective.

 

I have home made felt witches hats, as draft excluders, on my aileron /wing root holes - work a treat.😈

Wouldn't felt let gas through? Part of the purpose is to stop carbon monoxide.

[onetrack]

That's a firm Yes. Wool felt has no ability to stop CO2 getting through it - even though it has some uses in filtering some chemical smells and chemicals with large molecules.

 

CO2 has small molecules that pass easily through the relatively porous regular wool felt material. But if you employed wool felt containing activated carbon particles (charcoal) in it, then the CO2 would be trapped by the activated carbon.

[Blueadventures]

Hi Marty  This is one method.

DIY Firewall Boots.docx

[Marty_d]

28 minutes ago, Blueadventures said:

Hi Marty  This is one method.

DIY Firewall Boots.docx 226.79 kB · 1 download

Thanks! That's the same article OT linked to.