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Paul Thomas

Well Known Member
Many threads have been started regarding how bad ProSeal is; frankly, I don't mind working with it but I'm just finishing my first tank. Should it, or one of the three other, leak, I'll change my tune :D

I'm just wondering what people have found to be the most effective work process. Having almost completed a tank does not make me an expert, but I've been able to experiment a bit. Given the short work life of a batch, even with the AC on (mid-70 and unknown humidity in a non-insulated garage), I try to use as much of the fresh batch as soon as I can. Even halfway into the pot life, it doesn't spread as nicely as when you've just mixed it.

I've found that dividing my batch in two per rib works best. I butter the flange, cleco the rib in place, and make the fillet the outside edge. I then use whatever is left to wet seal the rivet the rib in place before mixing a new batch that's used to encapsulate the shop head and create the fillet on the flange side.

I like bigger batches because mixing error due to scale inaccuracy as lessened but I don't work fast enough. My slow pace also cans the possibility of doing more than one rib at a time, the ProSeal that oozes out would start to set and I wouldn't be able to make as good of a fillet.

What's your work process? It's not too late for me to improve. Someone posted about mixing on top of a tile versus in a pot and that suggestion is solid. Thanks!
 
Paul Thomas said:
Many threads have been started regarding how bad ProSeal is; frankly, I don't mind working with it but I'm just finishing my first tank. Should it, or one of the three other, leak, I'll change my tune :D

I'm just wondering what people have found to be the most effective work process. Having almost completed a tank does not make me an expert, but I've been able to experiment a bit. Given the short work life of a batch, even with the AC on (mid-70 and unknown humidity in a non-insulated garage), I try to use as much of the fresh batch as soon as I can. Even halfway into the pot life, it doesn't spread as nicely as when you've just mixed it.

I've found that dividing my batch in two per rib works best. I butter the flange, cleco the rib in place, and make the fillet the outside edge. I then use whatever is left to wet seal the rivet the rib in place before mixing a new batch that's used to encapsulate the shop head and create the fillet on the flange side.

I like bigger batches because mixing error due to scale inaccuracy as lessened but I don't work fast enough. My slow pace also cans the possibility of doing more than one rib at a time, the ProSeal that oozes out would start to set and I wouldn't be able to make as good of a fillet.

What's your work process? It's not too late for me to improve. Someone posted about mixing on top of a tile versus in a pot and that suggestion is solid. Thanks!
Click to expand...

Fay sealing is by far the easiest. I did my second tank this way. Would do again. Much cleaner.

http://www.vansairforce.com/community/showthread.php?t=7602&highlight=faying
 
IMO what Paul describes is fay sealing. What he is doing differently than Rick is to set the rivets while the whole assembly is still wet vs. Rick's method of allowing the assembly to cure a few days and then set the rivets. However, both are fay sealing just using different techniques and both methods work.
 
Hi Paul,

In the aircraft industry (big planes 767/747 stuff) there are different sealants with a varied curing time, 2hr, 12hr, 48hr, also a "A" sealant for coating the area first (very runny), letting that set then adding the "B" coat (thicker than the A sealant), each of these types of sealant has varied curing times. The part number usually reads (depending on manufacture) PR 1440B2, or PR 1440A2, the 1440 is fuel tank sealant application, B2 is the type of sealant with a 2 hr cure time, and A2 is the type of sealant coat with a 2 hr cure time.

Another trick of the trade is to mix up the sealant, divide the well mixed sealant into what you need for the job, put what you don't need in the freezer until later on, I wouldn't leave it in there for more than a few hours, if you do do this let it thaw out before using to prevent condensation forming on the job. Cooling the sealant slows the curing time.

Another trick to help sealant cure is to spray water on the sealed area, yes water helps it cure.

Always keep a test sample, I've seen jobs pulled apart because of sealant that didn't go off.

Cheers,

Nick..
 
I agree with Daniel

I used faye sealing on my second tank, and would highly recommend it. Having done it both ways, I wish I did them both that way. No messy wet riveting. Working with Proseal was no big deal.
 
Wet Riveting worked just fine....

This whole issue is about personal choice. I did one rib at a time. Mixed 66grams (60white 6 black). Buttered the tank skin along the rivet line. Buttered the flange. Inserted and clecoed every other hole which created the filet. Riveted it and then sealed the heads and dressed up the filets. On the end ribs with the stiffeners I mixed 88grams. On the rear baffle I mixed 198 (180+18) grams. Each rib took me an hour to complete including sealing the shop heads. Another hour removing the blue tape and cleaning all the tools.
I used Tite Seal (medium wght) on the access plate and fuel lube on the drain fitting. Tested it today and woohoo.... It all worked fine. Tanks complete on my 6A.
One hour was about the pot life on the proseal I mixed. Used popsicle sticks to mix in clear plastic drink glasses.
 
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