This spring DH will use Master Weld caulk 620 on all the exterior of the HILo. It is a Versatile component elastomeric adhesive/sealant. I called for tech support. It can be used at 40* to 20*. I looked this up on the internet and it seems like you would have to buy a case of this caulk.Made in the USA. I wonder if a place like fastenall would carry this. Possibly some building supply places? Will let you know it goes.

DAP makes an elastomeric sealant called DAP Extreme Stretch. It's available by the tube for about $6. at Home Depot.

I placed my first order for hi Lo parts in September with J&R and they shipped me a tube of 420 then. Searching the internet I could not find it anywhere else. This reminds me to call and order a second tube. Be sure to cut the nozzle tip for a fine bead.

J&R wasn't familiar with Lexel caulk. The Master weld 620 is an elastomeric adhesive sealant. It's description leads me to believe it is a premium caulk.