Tube sealing advice?

[n3480h1]

I'm at the point where I need to provide rust protection for the inside of the airframe tubes. I've got a good quality tube sealing oil from AS. I read somewhere that the tubes will need a small hole drilled in them, the oil is injected, then drained, and the holes are closed with rivets. Is that right? Is there a specific type of rivet used?

Any tips are appreciated.

Tom

 

[splischke]

You have the right idea. I drilled fill/drain holes in the aft ends of the top longerons. I positioned the fuselage vertically nose down against the side of the house, climbed on the roof and, using a large syringe, filled it up. It took a while for the oil to seep throughout the structure. After it was filled, I turned the fuselage tail down to drain the oil. This took time and I had to rotate the fuselage around several times to get as much oil out as possible.

If your fill/drain holes are 1/8", you can use CCP-42 SS pop rivets. Heck, a buddy used J-B Weld to plug his holes.

-Scott

 

[n3480h1]

Thanks Scott, that's good news. Except it freaks me out to get on a roof. Can't explain it, but I have acrophobia. Doesn't bother me to do snap rolls, Cuban 8's or anything else an aircraft will do, but I HATE getting on a roof or climbing an observation tower. I was once employed putting up business band radio towers and even fell 40 feet off of one, and that still doesn't bother me, but a roof . . . .

Makes no sense to me either, but apparently its a selective acrophobia.

I'll order the rivets and get it done.

Thanks!

Tom

 

[phzabriskie]

Thanks Scott, that's good news. Except it freaks me out to get on a roof. Can't explain it, but I have acrophobia. Doesn't bother me to do snap rolls, Cuban 8's or anything else an aircraft will do, but I HATE getting on a roof or climbing an observation tower. I was once employed putting up business band radio towers and even fell 40 feet off of one, and that still doesn't bother me, but a roof . . . .

Makes no sense to me either, but apparently its a selective acrophobia.

I'll order the rivets and get it done.

Thanks!

Tom

HI Tom, you can take a look at my gallery and see how I did it. I worked from the ground and twist and turned the airframe. I knew I had lots of oil in the tubes so I felt very good about fully coating the inside but never thought of going completely vertical against the house which would get 100%. I used RAW linseed oil which is the esential ingredient in what you have. I also used very small holes only big enough for a syringe needle. It took a while to pump up the longerons full of oil but I felt very good about creating no structural weakness in the tubes. I used JBweld to fill them, and rubber plugs in tubes that had open ends. Good luck.
-Pete

 

[Peter L]

G'Day from downunder.

Interesting discussion about oil in the tubes.

It seems to relate to longitudinal tubes but not to the cross tubes? Or do you drill a hole in every tube in the fuselage??

 

[splischke]

I drill 1/8" holes at all clusters when possible. It not only allows the oil to penetrate throughout the structure but -- and possibly more important -- allows hot gases to expand and prevent a blow-out at the molten weld point. This is especially true with shorter tubes when gas welding.

-Scott

 

[phzabriskie]

I drill 1/8" holes at all clusters when possible. It not only allows the oil to penetrate throughout the structure but -- and possibly more important -- allows hot gases to expand and prevent a blow-out at the molten weld point. This is especially true with shorter tubes when gas welding.

-Scott

Same answer, photo in my gallery of the cluster and where I drilled.

 

[Bil4381]

The time honored solution is boiled linseed oil. It's warmed over low heat until it flows readily.
More recently builders have added some preservative (25%) to the BLO. I've been told that is what the 4130 tube preservative from ACS consists of.
There is a wax based preservative called Petrotec Amber. If they are still around Whitco Chemical used to make it. As I say it'sd very thick and needs to be warmed until it runs.
Using this formula is not wasted as you can use it to protect or re-protect control cables or any steel parts vulnerable to rust. Failing that control cables can be wiped with aeroshell 17 grease.
Bill Evans