I may as well weigh on this as well since I have recently finished an S&S D with black Oxford PSL. I was having problems with orange peel too until I invested in a new gun. I will agree with the point that the PSL wants a high degree of atomization compared to nitro lacquer. The relative humidity was fairly high (for here) when I sprayed, ~ 60%. With a compressor gun, don't lower the pressure too much. With a HVLP gun, the LP is at the tip, not the in the line to the gun. I was about 40-45 PSI at the gun. I didn't have real good success with flood coating the lids. I actually had a worse time with orange peel if I tried to flood coat horizontal surfaces. I had to fine tune my gun technique to get the best surface quality. I think Target has another product intended for flood coating in production. The great thing about the PSL is the burn in of the coats (as long as you recoat within the recommended time parameters). This alone makes it great for our application. My technique (this is a trade secret, so don't tell anyone) to prevent sand-through without creating an excessively thick coating is to use a split coat technique. After stripping and prepping the surface, I prime the bare wood with a good coat of black. Then I spray a full coat of clear. Next a coat or two of black. If the surface looks right, (don't ask me how - you just have to judge from experience) then I will machine sand. The trick is that the clear coat will warn you when you have sanded through the top black coats by the slight color contrast that shows. I adopted this technique while using nitro lacquer, but with some slight adjustments, works well with Oxford PSL. Happy hosing. Mark Story. RPT Eastern Washington University Cheney, Washington -----Original Message----- From: owner-pianotech@ptg.org [mailto:owner-pianotech@ptg.org] On Behalf Of Farrell Sent: Friday, September 07, 2001 5:02 AM To: pianotech@ptg.org Subject: Re: Oxford Premium Spray Lacquer Well Mark, these couple posts have gotten me thinking that I need to get my gun (spray) out and take another stab at shooting something (if it doesn't work, maybe I'll take my 12-guage to it!). What kind of pressure are you running AT THE GUN? I would love to figure out a way to eliminate or drastically reduce the orange peel. When I wrote before that I had finally found sucess, I was referring to rubbing out a finish on that did not have witness lines. The orange peel can be sanded out, but man, that is a lot of work, and you always have the risk (reality) of sanding through in spots. Question for Greg and Mark. When spraying a piano lid, do you hang the lid vertically and spray both sides at once, or do you lay it horizontal and spray one side at a time. If you lay it horizontal, how long do you wait before flipping it over? If horizontal, do you put all your coats on one side, and then start coating the other side? Thanks. Terry Farrell ----- Original Message ----- From: <bases-loaded@juno.com> To: <pianotech@ptg.org> Sent: Friday, September 07, 2001 7:28 AM Subject: Re: Oxford Premium Spray Lacquer Hi Greg - I use an Accuspray conversion gun (HVLP, but runs from a compressor), and have been using a .036 needle/nozzle set with a #7 air cap. Little or no orange peel. Mark Potter bases-loaded@juno.com On Thu, 06 Sep 2001 22:51:02 -0400 Greg Newell <gnewell@ameritech.net> writes: > Greetings fellow listees, > I'd like to relate an experience I've been having for far too > long. > I've been trying to refinish a piano and As Terry Farrell > experienced > too, there was a great deal of orange peel. Finally I have found the > correct solution (for me). > It seems that I was using the needle, nozzle and air cap that > came > with my Accuspray turbine and gun unit. I was assured that this was > what > i needed for the task I was trying to perform. I just recently, on > the > advice of a different salesman who's company also sells these units, > changed all three parts to near the smallest orifice parts made for > this > gun. It seems that water based lacquer has very small solids or > something like that. Anyway it worked like a charm. I have been > trying > to achieve a solution based on other things like too high a > temperature > and adding retarder, too fast a delivery, too slow a delivery, > product > too thick (that one didn't seem right) and a host of other worries > involving spray conditions. The new gun parts changed everything and > all > things are now as they should be. > I write this only to give a "heads up" to others who may be > spraying > water based for the first time. It seems a very high atomization > rate is > in order. Straighten that out before you begin and you will have > saved > yourself a great deal of time, believe me! Oh! and don't use steel > wool > with water based products either. Go ahead, ask me how I know. > > Best, > Greg > > -- > Greg Newell > Greg's Piano Forté > 12970 Harlon Ave. > Lakewood, Ohio 44107 > 216-226-3791 > mailto:gnewell@ameritech.net > > >
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