Great Stuff Pro Gun Repair 

Well that is the best comment on here ;) Pinned to the top. I have a tone more pics and video to share if I ever get the time to edit the clips. In the mean time, maybe you could toss me a picture of your project on our Facebook page? facebook.com/HomeintheEarth/

These guns are such a pain!

Great idea!

I tried that long before going to the drastic step of disassembling. A week in acetone didn't work. I even tried gasoline.

@@SimonASNG Acetone and gasoline will do absolutely nothing. NMP will dissolve foam, CU6 will completely melt. Polyurethane is extremely stable and hard to get to react.

@@anthonyasher6348 Acetone melts it pretty well and gasoline will melt xps and eps instantly. Also, the primary ingredient in the gun cleaner is acetone. Those work well when they can get to the foam, but if the foam is stuck in the gun, the solvent can't get to it to disolve anything. I'll check out dynasolve if I get a chance one day.

You're welcome!

That doesn't work for me when it gets to the point of how much gunk (which is inevitably the case) with these trash guns. And even if that is the case, they need to have a proper 1/2in square to fit a wrench properly.

Yup, it moves out of the way so the foam can flow around it.

after disassembly as above unable to get the tip to reseat completely to seal when trigger released. My theory was that the barrel was extremely set into the body originally so I tried shortening the barrel length at the body end grinding off 3-4 threads (brass tube) which did not solve anything so then tried grinding tip and that did nothing. If anyone solves please post.

@@tg-bh2up No help here but I'm having the same problem. Tip started acting plugged so I flooded it with cleaner and wiped away external gunk. Saw a tiny fleck of material on the seat at the tip and picked it way and used more cleaner. Now it leaks cleaner past the tip without the trigger being pulled. And this gun had way less gunk to it than the OP's guns. I can attest to the crap material used for the barrel and tip --- like it needs its own special sized wrench to fit and then it still would round over. I have honestly wasted more cleaner and foam than I have actually applied. Only 1 step better than the crappy Great Stuff cans with a straw.

Manufacturing tolerances. For me, the 1/2 inch was just too small and I couldn't get it on.

Oh yea, I always tried to keep them clean. But go thru 20 or 30 canisters over several months of building and your chances of not having this problem go way down... I figured it was a risk that I would destroy it, so I might as well try.

Maybe the ball isn't round anymore and it is leaking around the flat spot?

Heck, I think I got those for free. They usually have something for "free" if you visit with their flyer in hand. I don't go often, but when I do, I always get my free thing. It turned out that I eventually needed this one ;)

Yea, I guess. Sorry it didn't work out for you.

Me too most of the time, but if you are doing a bigger job, you get the tools the pro's use.

Yup, you are exactly why I made the video. I had the same doubts about trying to take it apart. I had pretty much given up and decided it would be OK to destroy it trying. When it worked, I was so surprised, I decided to make a video.

Unless it's a rotational piece that rotates counter clockwise. You should never encounter a reverse thread. Just letting know.

The cans were fine. You can easily feel when they are empty. You can also have a situation where the can isn't empty, but the top of the can is clogged. Neither was the issue in my case.

Yea, I wouldn't buy it for spray insulation. Cans are fine and more economical (but not environmentally friendly). But the spray glue is only available with the gun dispenser and that stuff is really great.

If the can is sealed against the gun, and the plunger is closed, it doesn't cause trouble. If you take it off after each use, you pretty much have to throw away the rest of the can. Being able to stretch a can across a few hours or days is half the benefit of using this system. I wouldn't want to leave a bottle on for months though. That said, I do try to end my day (or job) on an empty can, and then I attach the cleaner can to the gun, spray that thru a bit and leave the cleaner can on until the next day I need the gun (which might not be for weeks or months). However, buildup still happens. Even if you always shoot the can thru, you will still get a little residual buildup that the cleaner doesn't dissolve. I know some pretty meticulous people who still end up with a fouled up gun.

@@SimonHomeintheEarth I always use up a gun foam can too. For small applications I use a one time small hand can of foam. Until I watched your video I did not know you could take apart the gun without breaking it. So I took apart my oldest gun and you are right, there was small amounts of foam still around the spring. Even though I always store the gun with the cleaner attached. Good video. Thanks.

The cleaner is really just 100% acetone. It is the exact same stuff that women use to remove nail polish, etc. If it is bad for your skin, then women would be dying younger than men ;)

Yea, my shop was in flux (I was still building it). The "workbench" was just 2x12s left over from forming the footings set across home made saw horses. I re-arranged the place with each new task and didn't use the vice often enough to mount it permanently... But things are settling down now and getting more setup. I even have dust collection and power distribution now ;)

That brand of gun cleaner is 100% acetone. Women use this directly on their hands as nail polish remover every day. While it can cause dermatitis with prolonged exposure, it is considered skin safe for daily use. I personally had no issues with redness or dryness on my skin. I also had no breathing problems from this level of exposure, which I rate as less than the exposure I get when my wife does her nails in the car.

The cleaner is from the manufacturer. It's is the great stuff gun cleaner. It's the black can in the video. It can be screwed on but also has a tip to spray it. It's only acetone, so if you have that laying around you can use that instead. That's what I use.

@@ajsemtb Sweet thank you

Exactly right.

I did also use gasoline to soak a really stubborn gun. I found it is more effective on the inflated foam and didn't do much to compacted build up. Several others on here have mentioned using heat to help loosen things up, but I had several guns and got them all working with this method. When I was doing this, there were no videos of anyone taking one of these apart. I eventually opened it blindly figuring that the worst that could happen was I would need to trash it, but it was trash if I couldn't open it up anyway. If all the video does is show you what to expect inside, that is good enough for me. You can come up with your own ways to fix it.

Me too, until I decided that it would rather bust it trying to take it apart than have it sit there useless. I really don't think the great stuff people wanted us to fix them. Planned obsolescence.

apply heat, as another commenter mentioned, it uses a light glue that is heat sensitive.

Sorry, nope. Didn't look closely enough.

It depends how set the foam is. When it is fresh, it works pretty well. But over time, even with regular cleaning after each use, the crud can still build up. Gasoline also works, but even that has limits.

if you watch the video, he disassembles the valve. The ball won't disengage with the trigger. it is on a light spring and disengages with the pressure from the foam can. This was the problem with my gun, but following his disassembly instructions later in the video, I was able to get my spring working again underneath the ball. You should be able to lightly push down on the white ball in the valve from the top though if you want to check it and it should go up and down. just use a cut part of a wire coat hanger.

Bryan is exactly right. The gun mechanism pulls a wedge out of the way so that the pressure in the can is free to move the ball out of the way.

Definitely easier said than done, especially when you are up on a windy roof or down in a dirty hole trying to get as much work done as you can. ¯\_(ツ)_/¯

@@SimonASNG Or under a house in a crawl space.

Most of what I am doing is far too unique to be of that sort of detailed interest. Lets figure out if it is a good idea before showing anyone how to copy me ;) But I figured lots of people use Great Stuff Pro guns ;)

Oh yea, I actually mentioned that in my original cut (when fixing the other gun), but it was too long, so I ended up cutting it out. I figured someone would freak out that I was letting it get on my hands, so I wanted to mention that it is just nail polish remover. ;)

Gumout carb and choke cleaner. #1 ingredient is Acetone, #2 is toluene. Toluene will soften silicone. You may be able to soak cured foam and melt it off, Idk but worth a try.. This stuff is much less expensive than the cleaner, but it doesn't screw on the gun. Makes clean up easier as after use, you can spray the gun tip. Something else that may work on metal parts is pvc pipe primer. That stuff melts styrofoam quickly. I'll have to try it.

The cleaner is just acetone (nail polish remover) and the spray foam just picks off. The worst is that if you get any glue on your fingers, and then get some dirt on the glue, it is hard to get that glue off for a couple hours and your fingers are "permanently" dirty. ;) But yea, I did expect this comment and mentioned the glove thing somewhere near the beginning ;)

Home in the Earth “just acetone” will wreck your skin. Don’t ask me how I know.

I think that is usage dependent. I built a whole house with mine and insulated another and had to fix 3 guns over 5 years. I have not had to fix these guns since I did it for this video.

Tried it, but It isn't just an issue of fit. The metal is just too soft and the corners of the hexagon just round off.