Question
I'm a small cabinetmaker and finisher in Washington state. I'm finally switching over to conversion varnish. I have chosen to go with Sherwin Williams dull rubbed CV, with a vinyl sealer under it. I have a small amount of knowledge about CV, and SW CV in particular, as I worked in the finish room of a shop before I started my own company a couple of years ago. But that was a while ago and I was more of a stainer and sander at the time.
1) I use an airless for spraying. What tip works best for CV?
2) I remember there being some problems between the vinyl sealer and CV when I was at that shop - have they worked that out? I've read how important it is to sandwich glazes and such between vinyl sealer that I feel I need to use it. Do you?
3) I've read there are different catalysts - which one do I need to use? (The SW store where I am getting my CV does not carry industrial coatings and are just doing so for me - we are way out in the sticks!)
3) Does the vinyl sealer need to be catalyzed? And is catalyzed vinyl sealer a different product from regular vinyl sealer or just the regular with catalyst thrown in?
4) Are you who are using airless sprayers spraying right out of the can, or are you thinning it and if so, how much (Xylene or High Flash Naptha, right?)?
5) I worry a little bit about the temperature we are able to obtain in the shop, as we are such a cold region during the winter and I don't have the money for a heat make up unit. Anybody fess up to spraying it in a little colder room than it recommends and not having problems?
Forum Responses
(Finishing Forum)
From contributor R:
If you can't keep the product above 68 degrees for spraying and 48 hours after for curing, I recommend that you don't use CV. It will shatter like a bad piece of glass in a few months.
Contributor R is right about temperature. C-V loves heat. If you try to spray this stuff below 50F, you're dead meat. C-V is a superior finish, but it is unforgiving.
Lastly, Global Resistovar by Valspar is much better than the SW CV. I also can buy it a lot cheaper. Go this way if possible.
First, Sherwin Williams vinyl sealer can be used both catalyzed and uncatalyzed. It is the same product. There are a couple of benefits when you catalyze it: 1. you get greater moisture resistance and 2. you get higher, faster build.
I do recommend sealing varying color coats with vinyl sealer. I often seal my first coat of stain with vinyl sealer and to boost the color, I often shade with the same stain and seal that color coat with another coat of vinyl.
I have used both in cold weather with only one adverse affect. The vinyl sealer sometimes does not sand without gumming the paper and I find that I have to rub all the sanded surfaces with synthetic steel wool.
Back to the airless setup. You probably can push the material through without thinning. But I would probably use a fine finish setup for better atomization and therefore would probably thin within the 15-25% recommended.
I've never had a problem with vinyl sealer. I use the T67F3 24% solids and this is catalyzed with v66v26. The other catalyst is for the topcoat v84v83DRE and is catalyzed with v66v21. If topcoat catalyst is used in vinyl sealer, you will shorten an already small for catalyzation effectiveness and then you will have finish failure. Leftover catalyzed finish can be saved by either adding same amount of uncatalyzed finish and catalyzing for the amount added new the next day, or you can put it in the refrigerator (slows down the catalyst reaction).
I know I just got done telling you to keep CV room temp. This still holds true and you must bring cold CV back up to room temp. This is going to make people cringe, but here goes: I use those space heaters, the ones that kick out 350.000 btu of heat! After spraying each coat (I double coat for build), I cook CV off after fan has removed enough fumes and heat doesn't escape out booth. I kick on spray booth to vent occasionally. This sets CV up quick and allows me to speed up process and limit junk falling into finish.
Also, keep the finish department immaculate - you will find out just how clean I mean - and mist ground and door jambs to keep any dust from kicking up while spraying. I use an airless with a whip end for ease of wrist motion, Reverse-a-tip on a contractor gun. This gives you a filter at the pump and one in the gun, and I also put one on the intake hose (nylons/pantyhose). Your tips should range from everyday use 413 down to a 310 for narrow areas. The tips are fine finish rac 5, I believe (they're green as opposed to black or yellow).
I think that Rodda Paint is the distributor in WA. They have a rep that strictly calls on small cab shops like yours. You may want to contact them or log on to Chemcraft's website and look for a local distributor. Whatever you decide, find a distributor that knows the product line. I was greatly concerned when you mentioned in your post that your local SW doesn't carry industrial coatings and were doing you a favor. Misinformation or lack of info and product is not a favor.
Rudd came out last year with Duracat V (withstands 40 MEK rubs), but most of our users still prefer the ease of application and superior durability of the Chemcraft. After all, how many people rub their cabinets with MEK or lacquer thinner more than the KCMA standard... Rudd still has its good points, though, and we do like most of their products. Rudd being in Seattle is a great benefit because they are much closer to us from a shipping standpoint. If there is a Rudd distributor near the questioner, I wouldn't hesitate to call them either.
Comment from contributor F:
I would like to add a note about Rudd Duracat. The product is very hard, but it is important to know that there is a recoat window of 4 hours, after which the next coat will not adhere to itself unless you scuff it. The product is very brittle and is prone to peel up if scraped by the fingernail. We had an oven cabinet that had to come out and be refinished as it was peeling badly. I'm guessing this was due to waiting past the window and or not sanding before recoating. Not fun.
Recently we have been having some interlayer separation (peeling up of the finish layer when blue tape is removed, during scribing, etc.) and after much experimentation and considering of the various variables we have concluded that our problems began when we started to use wiping stain concentrates in place of glazes. We typically stain/lacquer for a barrier coat then glaze, then add 2-3 coats of lacquer. We believe that the stain concentrates do not have the right properties to adhere the lacquer coats below and above when used in place of true glazes.
We have now switched to the Valspar system and we are using their glazes and pre-cat lacquer. By the way, in preliminary testing, their conversion lacquer is incredibly tough and we plan on using it on our bar tops and tables. The thumbnail test fails completely to scrape up the lacquer. This is the only one I've tested this way that passes this test. Their pre-cat is silky smooth and our finisher likes working with it.
