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Tank Sealant To Use?

GeneralT001

Active Member
For the gas tanks can you recommend a product to use...and can I order it in advance if I probably won't be using it for 6 mnths to a yr?

Also, is there a good device to apply it with...or just use your hand/popsicle sticks?
 
Based on advice from a friend, I bought a Semco Sealant Gun (avail. here, used: https://www.yardstore.com/semco-6-oz-inline-sealant-gun-used) and pre-filled cartridges from Aircraft Spruce (Get the Chemseal ones - far cheaper).

Some of the best money I've spent - it's relatively easy and far less messy than mixing/spreading your own, but it is a bit more expensive than getting a quart of proseal.

_Alex
 
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There are different types and three are useful.

Type B is the common one. It comes in at least two and I think three speeds of setting, 1/2 hour, 2 hours (our most common) and I think 4 hours.

You can also get an "access hatch" sealant, with the same consistency as the common type B, the same speeds of setting, but it's supposed to come apart easier if needed for opening access hatches. Also it's sort of pink.

The third type is Type A. This has the same color and setting time as Type B, but more of a honey-like consistency. It's used for spotting over rivet heads and along seams, after the regular Type B has cured. These pictures illustrate that.

In the following pictures, a "mill" is .001 inch, or 1/1,000 of an inch. 250 mills is 1/4 inch.

q6SNSSK.jpg


and

hUBQLDI.jpg


Dave
 
Based on advice from a friend, I bought a Semco Sealant Gun (avail. here, used: https://www.yardstore.com/semco-6-oz-inline-sealant-gun-used) and pre-filled cartridges from Aircraft Spruce (Get the Chemseal ones - far cheaper).

Some of the best money I've spent - it's relatively easy and far less messy than mixing/spreading your own, but it is a bit more expensive than getting a quart of proseal.

_Alex

Thanks, I've taken your advice and order that gun. Is this the correct Chemseal to use with it?

https://www.aircraftspruce.ca/catalog/appages/chemseal09-04612.php?clickkey=16658
 
That's the 1/2 hour working life. You might be happier with the B2 version. And you may need at least the quart size - I didn't notice which you are selecting.

You can get that stuff cheaper from Van's. They have the best prices for the sealant they carry.

Dave
 
How is PPG better than the stuff Van’s sells? Don’t all the brands have to meet the same mil spec?

I’m in the PPG camp. True they are qualified to the same Mil, but the Mil doesn’t address Avgas. I think the PPG PRC 1422 is better with avgas. No real data to support this other than experience.
 
Flane master

That's the 1/2 hour working life. You might be happier with the B2 version. And you may need at least the quart size - I didn't notice which you are selecting.

You can get that stuff cheaper from Van's. They have the best prices for the sealant they carry.

Dave

Second that. Not sure why folks need the gun. If you're neat, like Dave said, tongue depressor works just fine. I put some in a big syringe and used a caulk gun.
Tanks were one of the most fun parts of the build. I did have a broken leg so maybe it was cathartic therapy! I opened the tanks many times just to sniff the proseal.
Enjoy it. If you think tanks are bad, wait till you build a slider canopyà
 
I’m in the PPG camp. True they are qualified to the same Mil, but the Mil doesn’t address Avgas. I think the PPG PRC 1422 is better with avgas. No real data to support this other than experience.

Agree, 1422 is also good, if I remember correctly Boeing switched to 890 for better corrosion inhibitor. Either one is good. I grew up with Boeing/MD and that’s what we used in the airline world for tank work.
And also agree just because it meets a mil spec does not mean it’s the same quality.
And if you want tanks that don’t leak at least 2 qts min. and use liberally .
No gun for me, slather it on like chocolate cake icing.
 
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Thanks, I've taken your advice and order that gun. Is this the correct Chemseal to use with it?

https://www.aircraftspruce.ca/catalog/appages/chemseal09-04612.php?clickkey=16658

Great! As David mentioned, the Chemseal cartridge you linked on ACS is the 1/2hr version. B2 is what you'd need: https://www.aircraftspruce.com/catalog/appages/prosealant.php

If you plan your tasks for sealing the tanks well, you should use about 5 or 6 cartridges per tank (I assume you bought the Semco gun that takes the larger 3.5oz cartridges, called "Kit 2" in the link above). The remainder of the plane will take maybe another 5 cartridges (again, batching sealing tasks so you can maximize the use of a cartridge of sealant). Buy them as you need them, and store them inside your house (some say refrigerate, but I didn't). In my hands, I could buy them a couple months in advance, and they seemed to work just fine.

Also get the "econ sealant mixer" attachment for your drill, and you won't have to hand-crank to mix. https://www.aircraftspruce.com/catalog/topages/skinWedge.php

_Alex
 
Walt, what would you suggest in place of PS890. Van's don't sell it anymore. They now use flamemaster. Aircraft Spruce charges 5 x cost to freight it to New Zealand and 3 months to get it. Boing Distribution are the same. Is there a 3M Aerospace product as good?

As mentioned PPG 890/1422 is the only thing I will use, it's never let me down.
Don't know anything about the 3M products.
 
As mentioned PPG 890/1422 is the only thing I will use, it's never let me down.
Don't know anything about the 3M products.

I know less than Walt, but I did discuss their product (3M) with the lead chemist/engineer for this specific product. She was very forthcoming in the discussion with facts and experience. The key issue was reversion in contact with 100LL. She said although the 3M product was not tested specifically for 100LL that she had never in (a decade) her experience with the product did reversion come to her attention.

Having worked professionally with several 3M lab engineers ( mostly PhD's) on a project, their knowledge was quite impressive. Academic and hands-on.

A fact of little direct use.
 
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