Thanks for that explanation, Widget. Are you going to CES?
PITA is correct. It's tedious, it's messy, and it takes time. Set-up and clean-up alone takes a couple hours, and my shop is small, so there's no dedicated room to do this. Touch-ups can be either sprayed or brushed, but the raw material is a paste, much like spackle, and must be weighed, thinned and mixed...and colored for the black models. The loss ratio is something like 3 or 4:1 depending on several variables. One thing I've learned in the process is that doing it too fast ends up with a sheer mess. Nailing the moving mass on the first pass is nearly impossible for this particular cone because so much material...about 70 grams...needs to be applied to be Engineering Standard Spec. JBL factory tolerances are within 20%. Mine are within 5%. Glenn Phoenix told me that Westlake Audio rejects/rejected 50% of JBL drivers because they weren't acceptable for his systems.
In this particular video, I hesitated to post close up views for this cone, because it's got some visible flaws, but not bad enough to call a reject from a few dimples because the amount of Aquaplas applied to the cone ended up to be dead on for moving mass. My eBay listing photos is a damn-near cosmetically perfect example. Such is one-at-a-time processes for a little fish like me. Believe me...I've rejected quite few. Chalk it up to the learning process.
The process to get to the published moving mass spec for Aquaplas coated cones takes several days to get it right. Set-up the spray rig, measure the gross amount of Aquaplas, thin it and mix it for spraying, spray it, pray it stays on the cone, let it dry overnight, weigh it again, most likely spray some more....repeat. Takes a few days to build one kit that's acceptable to ship or install.
Why do I do this? The most successful speaker systems that JBL ever produced...Some are just now in need of repair after 50+ years in service. That, in itself, is worth the effort to extend their lives. It's an icon...it's a classic...it's legendary...Countless great records were mixed on these systems. I love that. Many people bought these speakers when new and still have them. The Military PX, college dorm rooms, their first "real speaker". The attachment runs deep with these. Same with the L36 and L26. People simply love them for any number of personal reasons. It becomes part their personal history. So...the investment in the repair of the speaker that could very possible last another 50 years is pretty miniscule is the grand scheme of things when it comes to enjoyment.
For those that have bought my kits, the feedback is beyond satisfying. It really is a labor of love...but still gotta eat...lol.
Thanks for putting up with me.