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-   -   Tip: Proseal ...The fact and the fiction (https://vansairforce.net/community/showthread.php?t=7602)

rmartingt 02-29-2016 04:52 AM

Quote:

Originally Posted by tgmillso (Post 1058020)
Hi Guys,
So I've read through this thread and I'm not exactly sure the extent of priming I should perform before assembly. I'm not priming any alclad or internal components, but my concern is around T-712 z brackets and the T-405 angle. I would normally prime these non alclad components but I'm concerned about interaction with the ProSeal/MEK. I'm thinking the best approach to fully Fay seal the T-712 and T-405 followed by wet riveting, then priming these components after the tank is complete. Let me know if I'm off base with this one.
Tom.

I primed the z-brackets except for the mating face on the tank baffle side.

I left the rest of the parts unprimed for now. Once I have the forward angle fit and drilled to the fuselage I'll paint the rest of the tank.

tgmillso 02-29-2016 05:55 AM

Just finished my first ProSeal session, and I can vouch for the one gram per inch methodology. It worked out almost perfectly. I can see how this could get cut back to 0.8g/inch or so once you get better technique with regard to laying on a constant bead.
Tom.

diamond 02-29-2016 07:04 AM

Do you mean 1 g/in.? surface to be covered?. Also, how thick of a bead are you laying down?

wirejock 02-29-2016 09:02 AM

Shop heads
 
Quote:

Originally Posted by dwranda (Post 1058031)
Thanks! Very helpful!! My scale doesn't do tenths of grams so I mixed up 1 ounce to see how it would go. Had enough to get the stiffeners on, but needed more to do a nice fillet seal around them. Then got the fuel cap flange and drain on. Unfortunately had to drill out 3 rivets on the cap. Not fun.

Remember to put a dollop on the shop heads before moving on. They're easy to access before the ribs get installed.

MeAndMyToys 02-29-2016 09:25 AM

I did about 1 gram per linear inch, BUT the stiffeners with a filet around them or the ribs when they are installed and the baffle all work out to about an inch wide strip of sealant. So 1 gram per Sq in. would be a good standard as well. This also leaves enough to put a dollop on each shop head. I used a pneumatic seal gun(worth it's weight in gold) laid down a bead about 3/16 in. diameter.

diamond 02-29-2016 11:03 AM

Thanks. I bought the pneumatic sealant gun and a mixer that appears to go on the end of a drill. The mixer is a round disc with 2 protruding screw heads. Can someone walk me through exactly how to use this mixer?

David Paule 02-29-2016 11:20 AM

I mixed smallish batches, no bigger than 40 grams each, and Popsicle sticks were all the tools I needed. In fact I've got one of those pneumatic tools setting on a shelf; never once thought it would be needed.

However I did use 3 types of sealant:

1. Van's type B sealant.

2. Access panel sealant for the hatches.

3. The thinner, lower-viscosity type A sealant to overlay the rivet heads and edges.

Skygeek had the last two.

Dave

longranger 02-29-2016 01:54 PM

Quote:

Originally Posted by tgmillso (Post 1058020)
Hi Guys,
So I've read through this thread and I'm not exactly sure the extent of priming I should perform before assembly. I'm not priming any alclad or internal components, but my concern is around T-712 z brackets and the T-405 angle. I would normally prime these non alclad components but I'm concerned about interaction with the ProSeal/MEK. I'm thinking the best approach to fully Fay seal the T-712 and T-405 followed by wet riveting, then priming these components after the tank is complete. Let me know if I'm off base with this one.
Tom.

I primed my z-brackets, then used scotchbrite to remove the primer (duplicolor) from the faying surface before final installation. You could also mask the faying surface before priming. I think it would be difficult to get good coverage on the forward-facing surface of the aft flange after installation.

messr723 02-29-2016 07:10 PM

proseal
 
Not exactly on topic but dip your hands in water with dishwashing liquid mixture during application and you can wipe the proseal off your hands with a paper towel. Its a great way to make a smooth filet I am not so sure of spelling, but try it next time you proseal.

tgmillso 02-29-2016 08:44 PM

Proud rivets
 
So I finished my first session of stiffener attachment last night, and the second session this morning. The ones I did last night, I dabbed a little extra proseal in the skin dimples before I inserted the rivets. My thinking was that most would work out, giving me a smooth finish, however I was mistaken. Some did, and those rivets came out fine, but others didn't, leaving the rivet approximately 3-4 thou proud. During the session today, I didn't add any extra proseal to the rivet holes, just smeared the sealant that had come through the holes when I applied it to the inside skin surface. I just pushed the end of a popsicle stick in the dimple, give it a 360degree rotation and called it good. In addition, I made sure when I put the stiffeners on, I pressed down a little harder against the back rivet plate than I did the first time, to push the rivets up hard before I began driving them. These rivets came out perfectly. I'm just going to hit the proud ones on the other wing with my heavy duty cage, die grinder and avery shaver bit combination. Anyway, just thought I'd throw this one up for others attempting their tanks. Just don't go overboard putting too much sealant in the dimples.
Cheers,
Tom.


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