Fuel tanks

[mayo3808]

Rick
We use B4 Flamemaster in the south because its so hot most of the time and we needed longer working times.
The normal working temperature is 77 F 50% humidity. Cooler temps will only slow down the curing process but could thicken the sealant working conditions.If you can I would warm shop up a little but it may not be necessary in order to get pro seal to flow out on the ribs. Tape off everything you don't want black goop on. Have fun

Brent
SN 053

[at7000ft]

Another tank question, is their a desired temperature range for a shop when using the B-4 or Flamemaster? (Like with epoxy?). My shop is currently in the 40s. (And where did they come up with a name like 'Flamemaster' for a tank sealant? Would be a good name for a fire retardant).

Also if Dan W. uses B-4 than that's what I am going to use (doesn't mention that in the BM does it?).


Rick H

[Tony Spicer]

Thanks, I will do that this Saturday. You guys are fast. It took me 1.5 hours to do the two inboard rib fitting installations. I also used the DIENQ and almost every rivet is proud.

Do you have any special advise on getting around the fuel pickup when sealing around that rib? I covered it, but it was still difficult.

If this first tank turns out to be as bad as I anticipate, I may need to get you to build one as I am not inclined to keep making the same mistakes. Leak tests in about 2 weeks.

Dan,

I suggest putting the fuel pickup in after the rib is installed. Like this:

https://picasaweb.google.com/tonyboytoo ... 7592242002

I used the Avery 100 deg die and had zero proud stems. There's a lot of sealant between the rib flange and skin. Most likely enough that the stack height will be exceeded. Result of that will be proud stems. You've got to squeeze most of the sealant out. Clecos will get some of it:

https://picasaweb.google.com/tonyboytoo ... 0834246946

The rest will be squeezed out when you push hard on the rivet before setting it.

Tony

[PlaneDan]

Thanks, I will do that this Saturday. You guys are fast. It took me 1.5 hours to do the two inboard rib fitting installations. I also used the DIENQ and almost every rivet is proud.

Do you have any special advise on getting around the fuel pickup when sealing around that rib? I covered it, but it was still difficult.

If this first tank turns out to be as bad as I anticipate, I may need to get you to build one as I am not inclined to keep making the same mistakes. Leak tests in about 2 weeks.

[danweseman]

Dan/ Others
We always use use B-4 (Current stock is 3M brand). plenty of working time. Also with method 2 just get the ribs in, cleaned up and the rivets "tails (inside tanks)n sealed! Do not do the back in the same setting. This gives you plenty of time to look over your work before closing the tank. It should take 2.5 hrs per tank to install all the ribs,seal the rivet tails , seal end ribs on out side and , clean up
Also in the shop we did 4 tanks Saturday. We used the DINQ dimple method and only had about 5 proud stems in all 4 tanks.
Dan

[MikeS.]

That's a good looking crew Dan!

[Tony Spicer]

I get about 1.5 hours out of a 30g mix, but it starts getting sticky around an hour out.

As for clean-up, I had cleaned up on the outside around the rivets into the ribs, but not the back. I just spent 1hr 15 min cleaning up that and all the clecos that I had left submerged in acetone. You have to put your hands in it and clean them with a cloth to get the job done. I know it is bad for you to do that, and washed up immediately afterwards. I never was a "glue sniffer" when I was a kid. I wonder if that 15 min over the acetone is what it is like. My head is spinning.

On the next tank, do one rib by yourself and see how it goes. Ditch the acetone for cleaning. To clean the clecos, extend the tip and give it a good wipedown with a paper towel. When you're finished with the tanks, the tank clecos will hold better than any of the others. The tank sealant will always stay a bit flexible.

Tony

[PlaneDan]

I get about 1.5 hours out of a 30g mix, but it starts getting sticky around an hour out.

As for clean-up, I had cleaned up on the outside around the rivets into the ribs, but not the back. I just spent 1hr 15 min cleaning up that and all the clecos that I had left submerged in acetone. You have to put your hands in it and clean them with a cloth to get the job done. I know it is bad for you to do that, and washed up immediately afterwards. I never was a "glue sniffer" when I was a kid. I wonder if that 15 min over the acetone is what it is like. My head is spinning.

Oh, and as to why it took 3 people... Check out the photos... I know... this is cheating.

BuildingTank_20150503_02.jpg

BuildingTank_20150503_03.jpg

[MikeS.]

If more working time is needed you can use B-4 (CS 3204 B-4). SkyGeek doesn't seem to carry the B-4 in pint or quart kits but Flamemaster should be able to send you to a source if a web search doesn't turn anything up.

http://flamemaster.com/wp-content/uploa ... -01-07.pdf

3M also has their version of the B-4 and Aircraft Spruce carries it here (more expensive than FM, but still cheaper than Pro-Seal):

http://www.aircraftspruce.com/catalog/c ... ckkey=4275

[PlaneDan]

I chose method 2, maybe that is why I felt that I had to do it all at once. If you can build it up to putting the back on and do that later, I guess that would split it up. My concern was that cured sealant would not bond with newly applied sealant as well as it would if the sealant it is supposed to bond to, has yet to cure. Maybe a wrong assumption.