J

JDBoston

Well Known Member
In building my 14 tanks, I have a choice to make:

Quick background: Building in my garage which is attached to the house, smells do travel if the main garage door is closed as in the cold winter. No heat in there right now I could buy a stand alone heater, but a little worried about a fire hazard from the solvents, dust, etc.

Moment of truth: Parts are almost prepped, ready to start the wonderful proseal process. ;)

I live in the cold northeast, temps in garage are probably between 20-50F for the whole winter.

Looking for opinions: Set the tanks aside until spring where I can leave the garage open and start working on flaps now, or no big deal and just get em done. No experience with proseal yet which is why I ask about the fumes. Obviously MEK/Acetone is quite a strong smell. I could leave a window open but the garage would get cold and am worried about fumes causing a fire hazard with a heater.
 
Polysulfide fuel tank sealant will cure at low temperatures, but for every 20 degree F reduction in temperature, the application life (tack time) will double. The longer application time is definately not a bad thing as it will give you more time to assemble and rivet the parts before the sealant starts to set. You can use a heat gun or a small space heater to heat the tank structure to accelerate the curing time after assembly as long as the temperature is not greater than 120 F.

Fuel tank sealant does not produce enough "fumes" to be a concearn with using a heater. Even during the initial cleaning and prep for sealant application the Acetone would almost have to be atomized (sprayed with a solvent sprayer) to create a fire or explosion hazard.
 
I haven't Pro-Sealed just yet, but have done composites work in my attached garage (which isn't far from you) that settles out at around 40-45 through the winter. Using a combination of a propane heater to get the garage up to temp (~60) and an electric bedroom heater (oil-filled; not the radiant type) to maintain temperature works well and is pretty safe. Laying old carpets out helps as well.

JDBoston said:
In building my 14 tanks, I have a choice to make:

Quick background: Building in my garage which is attached to the house, smells do travel if the main garage door is closed as in the cold winter. No heat in there right now I could buy a stand alone heater, but a little worried about a fire hazard from the solvents, dust, etc.

Moment of truth: Parts are almost prepped, ready to start the wonderful proseal process. ;)

I live in the cold northeast, temps in garage are probably between 20-50F for the whole winter.

Looking for opinions: Set the tanks aside until spring where I can leave the garage open and start working on flaps now, or no big deal and just get em done. No experience with proseal yet which is why I ask about the fumes. Obviously MEK/Acetone is quite a strong smell. I could leave a window open but the garage would get cold and am worried about fumes causing a fire hazard with a heater.
Click to expand...
 
I did my tanks last winter. I have a kerosene heater (which runs great on Jet A, by the way) so the garage was at 45-55 when I was working and in the upper 30s to low 40s the rest of the time. The Proseal took a long time to cure, and stayed a little tacky long enough that I was worried about it, but it turned out fine. Or at least it seems to be fine, I guess I'll know for sure when I fill 'em with avgas!
 
Just my $00.02

I was in the same decision process last fall/winter. I decided to wait until spring. While I have no direct experience working with pro-seal in low temps, I would offer, along with the other suggestions, that working with the pro-seal at lower temps would be difficult; the lower temps would cause the pro-seal to be even stiffer than normal. It is somewhat difficult in normal temps to spread the stuff and I would think that at lower temps it might be impossible. Since there is a pot life you are already working against the clock, add a stiff mixture and it could become very frustrating.

Another option might be to have all the parts and sealant inside the house (at room temp), then travel the parts and mixed sealant to the garage and assemble. After sealant out gassing bring parts inside. But this could be a little stinky.

My suggestion; work on the flaps and ailerons.

Cheers
 
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I got around low temps when doing messy work like fiberglass or Proseal. My wife found me two hair dryers from the 60s called Hatbox or plastic bonnet hair dryers. These were from the days of big curlers where women put a plastic bonnet over the curlers. The dryer was seperate and connected to the head with a 1" or so long flexible hose.

I just throw am old blanket around the item and stick the hose under it. The heater sits a couple of feet away and not near anything flammable. Check after an hour or so and turn the heat up or down. I cured a bunch of things using these.

They might still be available in junk shops, or somewhere on the Internet.
 
Now that's a flashback. My mother used those driers back in the days!

Just an FYI; my use of the term 'Pro-Seal' was used generically. I used the Van's supplied Flamemaster 3204 B2 sealant. The tech sheet has no reference to a minimum temp for cure, but common sense would obviously come into to play; the lower the temp, the long the pot life and time to cure.
 
Do this

Build them up when your temps are highest so the Proseal flows better 40-50 will be OK if you can at least warm the sealant up in the house first. When your all done riveting, put the whole fuel tank in a heavy lawn/leaf bag and tie it off tight...bring it in the house and let it set overnight. Proseal will cure fine, and no smell. I work with Proseal almost every day at my day job, and you need it warm to cure..it will cure in cool temps, but the rate is drasticly slowed. One of the best pre-cleaners is Coleman lantern fuel by the way.
 
If people have more opinions keep them coming for others to see if they face the same question.

I am going to cleco the tanks together for now and match ream to make sure all the rivets go in straight, and leave them until the March/April timeframe. In the meantime I will start working on the flaps, and will still get a taste of proseal as I most likely will use that for the trailing edges if applicable, but will figure that out when I get to that stage. I know that the tape is being used now instead but others have stated the 'classic' sealant method works well too.

Thanks for the input.
 
Wait

It will be easier for you and you have other stuff to do. I have pro sealed in cooler temps (40f) and previous poster is spot on cure time slows drastically. Took about 2 weeks in my hangar in the fall. Also it can get messy and it'll just be easier without having to deal with cold too. Just my opinion. Good luck and don't scrimp on the pro seal especially in the rear baffles if the 14 is like the 6.
 
As was previously pointed out, below 50 deg F all bets are off. Personal experience where proseal was exposed to low temps (30's as I recall) and never cured. On speaking with the then manufacturer, PRC, they stated that if the cure is inhibited by cold (temps below 50 deg F) in the first few hours after being mixed, that there is a possibility that the sealant will never fully cure. Some chemist type went into a complex explanation way over my head. In any case they explained why we had the problems with field repairs in the cold and so we learned.

It is also curious that the sealant requires moisture in the air to cure. Very low R/H's will also inhibit cure.
 
A good read

I don't recall Proseal having much of a smell to it. I've also used an open flame propane heater in my garage. I wouldn't spray paint with the heater on, but using Proseal will be just fine.

Before you start, if you haven't already read this thread, read it - a VERY good discussion on sealing tanks:

http://www.vansairforce.com/community/showthread.php?t=7602&highlight=fay+fan.

My one recommendation is go purchase a pneumatic gun to apply the Proseal. It REALLY helps keep the mess down. Regular caulking guns can be used but they tend to keep leaking even after you stop squeezing the trigger - even if you relieve the pressure on the plunger.
I purchased one like this on ebay for $35 including the plastic inserts and tips:

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The biggest challenge you'll have with Proseal is measuring out the mixture. I used plastic syringes (one for resin, another for catalyst) with the ends cut off and I would set the volume, then "shovel" each into the appropriate syringe with a tongue depressor, push each out into a cup and mix... Worked VERY well.
 
Tom,

I have read that thread thanks. I am going to try using Tom Martin's method that he posted a while ago with the individual cartridges.

Shown here:
http://www.vansairforce.com/community/showpost.php?p=921060&postcount=1

Will try doing the stiffeners in this fashion, and if I find that doing all of this while the proseal is still wet too much mess, I will use the other partial cure method. I can see where riveting together while still uncured would tighten up the seal more than just clecos but I am coming at it a bit uninformed I do understand.
 
Proud rivets

I did a set of -7 tanks in cold temps. It was nice to have additional working time before the ProSeal would start to set. One thing to consider though....I found when bucking rivets, the colder temps made the Proseal's viscosity thicker and therefore increased the hydro-static pressure under the factory head. I would have to increase the psi on my gun to get the rivets to set flush. It took the "finesse" away from the process in my case.
 
Along those same lines I am working on the elevator for the 10 and I need to use proseal to adhere the foam ribs to the skin as well as the trailing edge wedge. I was planing on doing that in the basement figuring that I would only be using a small amount for a short period of time. Is that a bad assumption to make? I haven't worked with proseal before, I used double sided tape for the rudder. Would I be putting myself and my family in danger by doing that work in my basement?
Thanks!
Dave
 
Wyzepilot said:
Along those same lines I am working on the elevator for the 10 and I need to use proseal to adhere the foam ribs to the skin as well as the trailing edge wedge. I was planing on doing that in the basement figuring that I would only be using a small amount for a short period of time. Is that a bad assumption to make? I haven't worked with proseal before, I used double sided tape for the rudder. Would I be putting myself and my family in danger by doing that work in my basement?
Thanks!
Dave
Click to expand...

No, Proseal doesn't have a lot of VOCs. I did my elevator trailing edges in the basement
 
I put a tank together in the winter in MI. Heated garage to 55 C when working. I had no issues. I kept the "proseal" in the house on a floor heater vent. This way the pro seal is easy to mix. I faye sealed, clecoed, and then brought inside. I put the fuel tank in basement in the furnace room. After curing for a few days, I brought back outside and riveted.
 
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