sealed rivets

[bob85]

MC what brand and type of aircraft sealed rivets do you use?,
are they available in different lengths suitable for riveting thick wall tubing 1/4" or more in total wall thickness?
the sirio 827 i posted pics of uses regular rivets which makes sealing the top hub connection to the radiator very difficult causing problems with long term reliability in our weather,
some of them are glued and riveted and rely solely on one stainless hex screw for electrical contact, the ones that are not glued dont last long either once the usual crud has worked its way into the joint, a well sealed clean joint would be much more reliable imho,

thanks.

 

[W5LZ]

bob85,
I know this was directed to 'MC' but I'm going to stick my nose into it anyway (sorry 'bout that).
There are problems with sealing a mechanical joint that isn't welded/soldered. That problem is because of the different expansion rates of metals and glues/sealants. If a glue/sealant sets into a 'hardened' mass, and if the glue's/sealant's expansion rate isn't the same as the metal it seals, it will eventually crack, loosing it's sealing properties. So, a fluid/soft/flexible type glue/sealant that doesn't run in heat or desolve in water is the 'best' bet. For an electrical/mechanical joint a glue/sealant that's conductive would be nice, but certainly not absolutely necessary. If the joint looses conduction it just means that it wasn't tight enough to start with, sort of.
So, what kind of glue/sealant is soft, flexible, water proof, and fairly common? That sort of depends on where you live, kind of. Where I live, a silicon 'goo' used for sealing joints in a swimming pool works pretty good. So does the caulking used for sealing glass to metal (automotive). Or maybe duck-tape? There are going to be problems with those too, just depends on which 'problems' you want to contend with. The best solution is regular and periodic maintenance. (I know, I know, it was hard enough getting the @#$ thing where you wanted it to start with, without having to take it down every so often.)
- 'Doc

Ain't this stuff fun?

 

[bob85]

doc i know what your saying,
one of the problems with the 827 is water can run straight down between the boss and the bottom radiator section,
its easy enough to seal the top and bottom with silicone sealant but condensation can still get past the rivets, i may just seal the top and leave the bottom unsealed, that would keep 99% of the crap out that washes in there over time,
im converting it to 6mtrs, its not an antenna i would choose as a long term base antenna on 11mtrs,

fun yep i enjoy it.

 

[Master Chief]

http://www.mcmaster.com/

In search box type "3195"

I have a couple of boxes for you and was trying to get an original Astroplane for you also.

 

[bob85]

:shock: an original astroplane, you would be lucky to find one, i will take the top bracket off youres :twisted:

thanks for the link

 

[Master Chief]

I know where the antenna is and only need the permission to remove it, and its yours.

 

[bob85]

that would be very nice MC, how does that work, you spot an interesting antenna that looks unused for years and go door knocking to see if they will let you have it in return for removing the thing??

 

[Master Chief]

that would be very nice MC, how does that work, you spot an interesting antenna that looks unused for years and go door knocking to see if they will let you have it in return for removing the thing??

You are exactly right. Or, they can pay me $50.00/hr and I'll buy the antenna for $25.00.

As far as a liquid sealant goes, I recommend this:
Permatex ULTRA BLACK Sealant

This product is sold by DX Engineering or you can buy it at any automotive store. Only the ULTRA BLACK (#598B) is non-corrosive. It remains flexible and can be removed. I'll throw a tube of this in your long overdue care package.

Their other black sealants should NOT be used as the curing process solvents will corrode electrical connections!

I've used this product to seal the stainless steel clamp connection on the I-10K trombone. I've assembled and disassembled many I-10K antennas and this joint is susceptible to moisture ingress. (I've never liked this clamp and have designed an all aluminum replacement.)

 

[bob85]

that stuff looks good, i never realised some sealants can corrode the aluminum,
i wish it was that easy to obtain old antennas here,
only avanti's and the odd armco 1/2waves have survived since the early 80's and there are none just hanging around on rooftops waiting to be put to use once again.