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"Proseal" differences?

kbalch

Well Known Member
As I'm getting ready to jump into my first -14A tank (I outsourced my -8 tanks many years ago), I'm preparing to order the necessary supplies.

I intend to purchase one of the Semco pneumatic guns and will be looking to obtain sealant cartridges for it. A couple of questions:

I think I've read all of the relevant threads around here, plus quite a few project websites. Whew. It just can't be that complicated, can it?
 
3.5oz a session seems about right, maybe even a bit much. I only mixed enough for one rib at a time if I remember right. I don't know about the differences but Van's stuff is cheaper and works really good. I think Van's says it takes one quart for RV-7 tanks and there is no flippin way I got it done in that amount (and I think I have a pretty clean build on the tanks, you can check my build log on these forums here). To me this is not the place to be chincy by trying to save a few ounces. The -14 tanks are a little bigger so I would definitely plan on the need for two quarts worth.

Also, life is easier when you keep things cleaned and masked when necessary. I put multiple layers of gloves on before starting a rib. I no joke went through about 200-300 latex gloves building the tanks.
 
Spec

If it meets the milspec the differences are negligible. I wouldn’t use anything faster than a 2. That is the useful working time. In the airlines with a big repair we’d use a 48. Yes they do offer it.
 
Also, life is easier when you keep things cleaned and masked when necessary. I put multiple layers of gloves on before starting a rib. I no joke went through about 200-300 latex gloves building the tanks.

Just beware, when masking, do NOT use Scotch tape. I will be writing a post about this in the near future (hopefullly--I still have an evening or two's work to remove the tape reidue ahead of me), but suffice to say, when you prep an aluminum surface to maximize adhesion of the sealant, you also make the Scotch tape stick like you never imagined it could stick. Don't ask me why I used Scotch tape...
 
Just beware, when masking, do NOT use Scotch tape. I will be writing a post about this in the near future (hopefullly--I still have an evening or two's work to remove the tape reidue ahead of me), but suffice to say, when you prep an aluminum surface to maximize adhesion of the sealant, you also make the Scotch tape stick like you never imagined it could stick. Don't ask me why I used Scotch tape...

Good point, I might also extend that when I masked I used purple painters tape and blue painter tape. The blue was 3M, and the purple was Duck Masking brand. The purple stuff did leave a lot of residue when peeled off, luckily I discovered this before doing too much with it. Removing the residue was exactly as you say, a pain!
 
As I'm getting ready to jump into my first -14A tank (I outsourced my -8 tanks many years ago), I'm preparing to order the necessary supplies.

I intend to purchase one of the Semco pneumatic guns and will be looking to obtain sealant cartridges for it. A couple of questions:

I think I've read all of the relevant threads around here, plus quite a few project websites. Whew. It just can't be that complicated, can it?

I posted some tidbits a few months ago about what I learned about sealant. It's post #11 if you're interested. Cheap Semco sealant gun and tips about using rollers instead of popsicle sticks.
 
Syringe

I used the big syringes. Tip is perfect. It drops into a caulk gun for more leverage. Cheap.
Most of the sealing was just tongue depressor application. The syringe gun was used to apply the bead then spread with a shaped popsicle stick.
I also used just a tad more than 1 quart of the Van's sealant.
 
Quart ziplock bags, one per batch of roughly golf ball size. Mix in the bag, snip a corner, and use like a cake decorating bag.

One quart kit of Flamemaster from Van did two RV-7 main tanks plus two 14 gallon leading edge (3 bays) aux tanks.

Charlie
 
Just me

Quart ziplock bags, one per batch of roughly golf ball size. Mix in the bag, snip a corner, and use like a cake decorating bag.

One quart kit of Flamemaster from Van did two RV-7 main tanks plus two 14 gallon leading edge (3 bays) aux tanks.

Charlie

I never got good results mixing in bag. I mixed on scrap hotel key or other hard plasctic then transfered to baggie. Worked great.
 
One quart kit of Flamemaster from Van did two RV-7 main tanks plus two 14 gallon leading edge (3 bays) aux tanks.

Charlie

Wow! Teach me your ways. :D

I guess my mixing in a cup each time probably left a fair amount of waste compared to the bag trick.
 
I posted some tidbits a few months ago about what I learned about sealant. It's post #11 if you're interested. Cheap Semco sealant gun and tips about using rollers instead of popsicle sticks.

I've seen that post before and have bookmarked the rollers and other miscellaneous tips. I used popsicle sticks to do my elevator foam ribs and that was enough for me. :D
 
Thanks, guys. I'll get the various orders in today and should be underway on my first tank sometime next week.
 
Wow! Teach me your ways. :D

I guess my mixing in a cup each time probably left a fair amount of waste compared to the bag trick.

Actually, the vast majority of waste is on the interior (not-end) ribs, & the stiffeners. The only place the tank can leak is through the rivet holes, so the only sealant that matters is in the hole, and for insurance, a little 'donut' of sealant around the rivet between the faying surfaces plus a small dollop over the shop head.

I wish I could claim 'brilliance', but I was taught by a 2-time builder.

Charlie
 
Prep and coverage is key

The reality is that the prep and coverage are all that matters. You can apply it a million ways, and I prefer a simple acid brush and typically squeeze the mixed product into a cup or on a piece of scrap whatever. I prefer to scotchbrite clean and wipe down with Coleman lantern fluid prior to application. When applying, more isn't always better...just even coverage and no voids. I prefer a brush coat of "B" (Toothpaste consistency) on mating surfaces, rivet together, and later topcoat the joint and rivet tails with "A" (thin milkshake consistency) . I see little need to mask anything, and some MEK will clean any slop you need to wipe up. Between all the written lines of the Specs, processes and tools are the layman's method I described. For the record, my day job is maintaining the fleet of KC-10 refueling tankers...i'm literately standing next to cases of sealant as I write this. Don't let the myths and horror stories scare you !
 
Apply some masking tape onto a piece of scrap aluminum around 8" square. Tare your scale with a metal putty scraper and a popsicle stick on it. Use the scraper for Part A, and popsicle stick for Part B. In my experience, it yields perfect proseal every time.
 
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