hello

I have used to shoot cv sealer wich have a 4 hour recoat window but decided to self seal but have mistaken the recoat window of the cv wich is just 2 hours. It was thinned with 10% retader(max recommended) and was barely dry enough after 2 hours to be sandable( could put fingerprints in the finish when pressing firmly).

I ended u recoating after 3h30-4h. So far the cv has cured for 72h and no wrinkling or signs of adhesion issue between coats so...

does recoat window problem should be showing early or could they appear after weeks.

also does recoating during the window is better than waiting after full crosslinking to recoat and rely on mechanical bound or the drawback is only the waiting time. Do I increase the risk of adhesion issue when recoating after full crosslinking if I let say forget to sand a spot.

Almost sound like you forgot to add the catalyst or you were drying in a too cold environment (below 65ºF) 2 hours is a long time for CV to be wet/tacky.

Usually the recoat window is a before time and an after time. Recoat before 2 hours or after 24 hours for example.

Still not dry after 2 hours?

You're doing something wrong

well it was dry after 2 hours but if I pressed firmly I could leave a finger print but it also powdered when I sanded. keep in mind that I retarded it to the max allowed by the manufacturer . but the scrap I finished along the real pieces that way are hard and resistant

but my questions were

does recoat window problem should be showing early or could they appear after weeks.

also does recoating during the window is better than waiting after full crosslinking to recoat and rely on mechanical bound or the drawback is only the waiting time. Do I increase the risk of adhesion issue when recoating after full crosslinking if I let say forget to sand a spot

Recoat window issues usually manifest themselves immediately with wrinkling of the coat below.

But it's CV and the next problematic timetable is usually 6 months.

thanks for your awnser leo

I have checked the precisions of my mixing cups using the ones at my job that we use to measure precise chemotherapy dosages (some +- 1 ml precise cups) and most of my finish measuring equipement read under the real volume. like 150ml on my cups is more like 175ml so i may have been under catalazing and over retarding wich may explain long drying time.

Same problem with my finish mixing cups. 2 different kinds seem to read less than is in there. Reads 30oz but precise measurement indicates it's 32oz. But it also seems to be linear in that 15oz read is 16oz in real measurements. So I've adjusted how I read the cups. I use different glass cups to measure out my catalyst and they are pretty accurate. Only hold 4oz max.

Likely that wouldn't cause such a big difference in drying times though. My catalyst ratio is 10:1.

mine is 8oz to 128oz( 1 gallon) wich is supposed to be 6.25%. the manufacturer stated 6% in an email. I use 6.25 so that may compensate for the underreading of my cup.

just like anything there is surely a tolerance thing but no manufacturrer will give it precisely for fear of claim

and by the way I followed your advice by using cv as self sealing. much more simple this way and Reduce the risk of error (like I did by mistaking the sealer recoat window and the cv window)

I pretty much self seal all my clear finishes. It's just easier in the long run. 2K poly needs a sealer so I'm forced. All pigmented get primer underneath. Every once in a while I'll self seal pigmented if it's a small molding or toekick or something that doesn't need a perfect finish. The primer really helps in flattening things out.

lol I just realised that the distributor pds is out of date and the manufacturer new pds states a 4 hours recoat window so its probably why I did not encounter wrinkling.

maybe the dry time was just because I was a bit ligt on the catalisys since my cups tend to underread by about 1 oz.