Newborn Parallel Frame Caulking Gun

Bought 2 of these to inject THIXO FLEX 2-part epoxy into cracks in our peeled log handrails and posts on 3 decks and front porch at Lake Tahoe, CA, elevation 6,300'. Temps in the 60s & it took a lot of pressure to push out small streams of epoxy thru the mixing injector tips, even with tips cut for Max. flow. Then the guns would jam about 2 1/2"" into the caulking tube -- immovable!--but begin working again after being warmed up. Discovered yesterday that they jammed even without a caulking tube until I sprayed all moving parts with WD40. Too cold to try again today @45F, but will try again on a warm day. Also, the ""collar"" where the tip of the caulking tube goes into the end of the gun is too small to put in the flex cylinder easily. I talked with Paul, Tech Support, and he agreed with me that grinding off about 1/16"" on the end of the gun collar would help and it did. Nick, Tech Support, told me to try the model NBC-250 gun that has an 18:1 pressure ratio instead of 10:1 for this gun, so I've ordered 2 that will arrive 10/29/2020.

Unable to use it because it does not fit the Thixo cartridge which is why I ordered it !!!!

The parallel frame guns are noticeably better than than the more common tube-in-a-tray hand guns when used with thick cualking compounds like 3m's 5200.