Removing wing capsule gauges, redux

[dkkim73]

So... I got my new -009 marked gauges from Lasar and am contemplating the process of removing my existing gauges. 

Reviewed a how-to here (looks brutal): 

When I replaced the last one, there was only a small amount of polymer in the bottom. I fully "potted" the replacement with silicone RTV, to avoid any gaps that would allow a freeze/thaw expansion process. 

Any experience here to guide me in how hard these will be to remove? I'm hoping I can get a thin pick blade in the side and pry it without the "take off and nuke it from orbit" approach @0TreeLemur illustrated. Hoping silicone will be more tractable, but maybe I'm being too optimistic. 

Hangar is a good 20-25 min from home so hoping to think through the process in detail first and not have to run and grab tools, etc. I could also batch this with my next bit of shop work but it's otherwise straightforward so the CB/owner in me wants to do it

[0TreeLemur]

7 hours ago, dkkim73 said:

So... I got my new -009 marked gauges from Lasar and am contemplating the process of removing my existing gauges. 

Reviewed a how-to here (looks brutal): 

When I replaced the last one, there was only a small amount of polymer in the bottom. I fully "potted" the replacement with silicone RTV, to avoid any gaps that would allow a freeze/thaw expansion process. 

Any experience here to guide me in how hard these will be to remove? I'm hoping I can get a thin pick blade in the side and pry it without the "take off and nuke it from orbit" approach @0TreeLemur illustrated. Hoping silicone will be more tractable, but maybe I'm being too optimistic. 

Hangar is a good 20-25 min from home so hoping to think through the process in detail first and not have to run and grab tools, etc. I could also batch this with my next bit of shop work but it's otherwise straightforward so the CB/owner in me wants to do it

If you can get it out without the nuclear option, great!   Didn't work for me.    Mine are still great. 

No fear.  Those receptacles are pretty tough.

[GeeBee]

Motorcraft Silicon Gasket Remover will soften the RTV sufficient to easily remove anything potted in RTV. It sometimes requires a few applications and an overnight sit but it will work. I discovered this stuff trying to remove lenses potted in RTV on my landscape lights. It works really good and does not seem to harm paint. Amazon has it.

[Yetti]

Set of xacto knives.   cut around the gauge as much as possible.

And a heat gun should help things along.   just not too much heat.  like hair dryer heat. 

In other news, I took a Sharpie and marked the Gallonage outside the ring in case I have to go Generic.

[dkkim73]

For some reason, I had not subscribed to this thread and didn't see @GeeBee and @Yetti's suggestions! Thank you for those. 

I did pull the Left gauge (the one I re-potted) today. That silicone held it well! The contralateral Right gauge came off with the 100 mph tape that I asked the detailer to pull. So that's a good comparison... assuming the Right gauge is factory. 

Here are some pictures for fun. I used a drill and screw in lieue of the razor+screwdriver blade method. More of a penetrating bomb than the nuclear option but equally bad for the dial I must admit...

Took a long time to get most of the silicone out. And there are still fine areas of adhesion I can feel. Did multiple rounds with plastic scraper (all my hard brushes are a bit too wide), contact cleaner, water, and rags. 

Any other thoughts and the "last round" of cleaning. I *think* the old RTC silicone will bond to the new, but the devil is in the details...

David 

 

[Fly Boomer]

2 minutes ago, dkkim73 said:

More of a penetrating bomb than the nuclear option but equally bad for the dial I must admit...

OUCH!

[N201MKTurbo]

I use MEK for the last bits. Just be careful with the paint.