Home > Pat's TECH TIPS BLOG > What the "Best" Gun on the Market for Spray Foam Insulation and Polyurea Roof Coatings?

What the "best" gun on the market for spray foam insulation and polyurea roof coatings?

This question is asked on a weekly basis.

The best is in the eye of the beholder, but I'll give my opinion on the 4 most common guns, what I personally like/dislike on each and let you form your opinion from there.

Graco Fusion AP

By far, I have found this to be the most popular gun used globally. We sell parts for it all over the world for it.

  • PRO's: Very popular, well known. Its easy to take down and rebuild. We have customers that use this gun and have no issues at all, then we have some that have nothing but problems with crossovers. I use the Fusion AP when I started contracting and my OEM product - brand new - crossed the 1st day on my first job. I tend to blame the person behind the gun first, but it was winter time, cold and it could have been several issues that caused the problem. The chamber is easy to replace and can be done in a few minutes. The entire front end can also be easily replaced if you have a cross-over, so you don't have to take the entire gun apart to clean it. Just screw a new front section on and spray within 5 minutes. I liked not having to buy 3 complete guns when all I needed was 2 and then I kept 4 complete front bodies in the rig ready to screw on if I had any trouble and I could be back spraying in a few minutes.
  • CON's: The weakest point I see in the gun is the side cartridge. The cartridge spring applies the pressure of the side seal to the chamber when the front retaining cap is screwed on. It doesn't take much wear for the side seal to leak. Scratches on the 2 parts, sanding the parts, resurfacing the parts, all contribute to less force applied to the sealing surfaces. This can cause by-pass issues, but you also need to consider the chemical is too cold, filters clogged, off ratio... all contribute to cross-overs. The front end section is very easy to pull off without having to remove side cartridges. That means the force that creates the seal is not so great. I'll compare that with some other guns that you will never get the chamber out without taking the side blocks/cartridges out due to the tight fit. The loose fit is what I believe causes the Fusion chambers to scratch so easily. Many people blame the side seal, but the score marks are only on one side and side seals aren't smart enough to know to scratch just the A side.

GlasCraft Probler P2

Great gun and very popular due to great engineering by GlasCraft when they owned it. GlasCraft was bought out by Graco a few years back.

  • PRO's: Simple operation, easy to disassemble. The gun has a very tight seal between the side seal and the chamber. Unlike the Fusion AP, you will not just pull the front section off without removing (or loosening) the side blocks. Thats why I don't see anywhere near the issues of cross-overs with the P2 gun as I do the Fusion AP. The chamber is good quality. The ones we get sent to us have the GlasCraft logo on it. I don't think Graco would still make it and put the old name on it. Either case, I don't see GlasCraft chambers come in with score marks like the Fusion AP.
  • CON's: Changing the chamber is a major deal. Remove the side blocks, remove the front section and unscrew the chamber. No way to just easily change out the front section or just the chamber. I don't like the chamber, tip and cap - 3pc design. too many parts you have to buy to support the gun and the chambers are not cheap.The complete gun is expensive at $2700.00 and just the handle by itself is around 1400.00. The side blocks and filter screws were redesigned in 2013 and Graco discontinued the old style, so you'll need to watch that if you order a new filter screw from the. We make the old style screw and side blocks as well as the new style, so you do have a choice.

Graco Fusion CS

Not a very popular gun in the market. Its hard to even find Graco distributors that will stock the gun or parts for it.

  • PRO's: The CS fluid is supposed to keep the chamber clean so it doesn't clog up. I guess that's why they still include the clean-out drill bits with the chamber. Side seal cartridge is a screw in part, so it gets a good seal and I don't hear of the guns crossing over near as much as the Fusion AP. The CS fluid does help with closed cell foam wanting to plug the chamber as fast. You still need to clean it, but not as often.
  • CON's: The CS fluid tubes by Graco are not easy to refill by design so you have to order new tubes - pre-filled - from Graco. We supply just the fluid and our own tube that can easily be refilled and reduce your operating cost dramatically. The repair parts are not cheap. The adjustment on the rear of the gun was supposed to be able to adjust the amount of air injected into the foam while spraying to increase the yield. It doesn't work and last I heard, the reps were telling customers to leave it alone, admitting that it doesn't work. The black plastic parts on the front are easily broken and the threads strip out very easy. You'll need to keep a dozen of those on hand. Some customers claim they had to remove the guts from the manifold check valves to make it work. I don't understand that, but thats what was said and the guy sprays a lot of foam. (He just changed all his guns over to the PMC Polymac AP2) We don't see much on the CS guns in the US. We have some customers in Russia, Poland and some in Canada that use it. I can only think of a couple in the US market. I couldn't support my house cat on CS parts sales and obviously, the Graco reps feel the same way since they don't even want to stock the gun or parts. The o-rings have to be special. Graco supplies good ones and our O-rings from DuPont work extremely well on it. The blue fluid will melt your Viton o-rings, so watch what you buy that you think is a great deal.

PMC-Polymac AP2

A good gun and design that is gaining in popularity. Designed and built by former Gusmer employees.

  • PRO's: Screw in side cartridge make a good, tight seal. This gun also has very few issues on cross-overs compared to the Fusion AP. Side seals are available steel and polycarbon. Front body section can easily be removed (like the Fusion AP) to replace the chamber or switch out the entire front end so no need to have 3 complete guns. Just have the complete front section as a backup. The gun is smaller, more compact than others. Parts prices are very reasonable. The chamber is designed very well. The 01 chamber (or 02,03...) requires a 01 cap (or 02,03..) for the spray pattern. Going up one size on the cap (01 chamber and 02 cap) makes the pattern a wide pattern and reducing the cap size by one will reduce the pattern. The front body is available in aluminum and steel. The aluminum parts (like SPF Depot's) are hard coat anodized with a PTFE top coat to make parts clean easier. I thought I owned that idea. Hard anodized is a much harder surface than regular anodize and will give you longer life to the product.
  • CON's: PMC had some issues with patterns, but found that the chambers were not properly drilled. That problem has been corrected. The gun has 3 sections. The handle, the valve section and the piston section. The valve section slides onto the handle section and is held in place with some screws. The V notch that the parts slide onto is small and can be easily damaged if you get frustrated and decide to use your hammer and force parts together. The lock ring can unscrew itself if you don't have the stabilizer bar attached. I had thought of drilling and tapping a small port to put a set screw in the lock ring to fix that, but that problem doesn't exist with the stabilizer bar.

SPF Depot is a factory rep for PMC-Polymac, but I tried to be fair across the board on what I think of each gun without intentionally trashing the others and I have to say, we sell over $100,000/year on Graco OEM parts.

I get asked often if SPF Depot plans to build their own gun. Short answer - Nope.

Several guns are on the market and several work very well. Why try to redesign the wheel. If I could design one, it would be a gun that cleans itself at the end of the day and walks to my trailer. We do plan to resurrect some of the older guns that people still have and like.Hope the opinion helps. Let me know if you want me to voice opinions on other items. Just to be safe, I have to add my disclaimer:Any use of the word "Graco®" on this web site refers to Graco® Inc. SPF Depot is not associated with Graco® Inc. and is not responsible for the quality of Graco® brand products or their respective warranties. Graco®, Fusion®, and CS® are words which may be associated with Graco® Inc. and/or its products and which may be copyrighted and/or trademarked by Graco® Inc. All uses of these words alone or in combination are intended to refer to the company Graco® Inc. or its products.