Waterborne and Shop Temperature or Humidity
Some waterborne products are sensitive to temperature and humidity conditions in the finishing shop. March 9, 2010
Question
Most of my jobs involve walnut and waterborne finishes. Walnut often does not look good with this combo, but I did some tests with some new samples of Fuhr 255 and 260 along with some Target EM2000 I had sitting around. The Fuhr products looked great, almost better than the samples where the first coat was shellac. Oddly enough, the 260 looked best, even though Fuhr suggested it wouldn't look as nice on darker woods. The EM2000 looked pale and plastic. I switched to Fuhr.
I just made some new samples with the Fuhr products and they look like the EM2000 did. Has anyone had this problem? Do these finishes just lose that solvent look really quickly? The bad looking finishes weren't expired, but they weren't fresh. I should also note that the temperature in my shop this time of year is about 58 while it was likely closer to 70 when I made those other samples. Thanks for any help!
Forum Responses
(Finishing Forum)
From contributor C:
I use Fuhr basically for everything. I had an issue on a cool day with 260 once as well. The 260 was most likely too cool as well as the air temp and product temp. As for losing the solvent look I don't think so. I used 255 and 250 before going to 260. Now I have switched to 345, it is not exterior grade but it has the look of 260 and the feel of 250, cost less too. It sprays about the same as well. I would think the temp.
From the original questioner:
These tests use the finishes only, as sealers too. Tried heating everything and it looks good so far, but we'll see how it looks tomorrow. I don't see 345 on Fuhr's website. So it has the warmth I want and the slip of 255? Did you have similar results like me where the 260 looked better on dark woods than 250 or 255?
From contributor C:
You may have to ask for the 345, it is a newer product. I really like it, it is a varnish and I recall he told me it is a hybrid (not sure what that means in terms of chemicals. As for dark woods and colors and such I cannot really comment. I have not really done very much darker colors and have not even done any comparisons. I still have a small amount of the 255 and 260 I try to use them on small projects when I am sure I will have enough. But for a full kitchen I order 345 now and use it for seal coat and top coat. I am even changing over the stain from 155 to 135 as well. I have been buying stain in 5 gals for some time so it takes a while to use it as I am a one man shop. As for pigmented product I am getting good results from the 9300 it is built on the 380 product interior use. I have bought from FURH and a distributor and for the primer I have had the best results from Aqualock and have used BIN primer but if you want to be all waterborne then that is a problem the BIN that is but it sure does the job especially for an existing piece.
From contributor B:
I have been using Fuhr for a long time now and have never heard of their 135 stain base, is it new? If so, how do you like it? The 9300 is basically 260 pigmented while their 9200 is the 380 pigmented. As for another question, do you use a AAA system to spray their products? I might be buying one in the near future and curious to see some feedback on different brands.
From contributor C:
Yes the 135 stain is new as well. I have only used it a small amount due to lack of work and the amount of stain I buy relative to the job. Let me add that I have started keeping a stain sponge handy even dip it in water but just damp not dripping and just after you spray wipe the areas where the stain may be wetter than you need and found this helps as well. As for the equipment, I use CAT HVLP guns and pressure pots. I told my supplier when I first bought into using Fuhr that I had never been a finish guy but I had done some finishing even entire kitchens. I have told Adam, Fuhr products make me look good. Ease of use from application to clean up, dry time is great. I have been using their products for 5 1/2 years now with very few issues. And I am certain they were mostly me and my environment. I have had many compliments on the finish even after a couple of years when I go in and show a house to a new client they tell me how they love it and how easy they are to clean.
From contributor H:
I have a mill shop in New Orleans and I am considering converting to waterborne clearcoat. Cold is not an issue for us but humidity is. Do you know if waterborne is particularly sensitive to humidity? What type of dry time should we expect? Do you believe the finish is as hard as cat varnish? If I experience a finish flash problem can I sand and recoat or do I need to remove the finish?
From contributor C:
My shop is just west of Atlanta and we have those high humid days as well most likely not as many. Some days are too hot and dry for my likes but the only time it seems to be an issue is when I am spraying a large piece and I crank up the material so it does not dry as quickly. Yes you can scuff and add additional coats, you even have a small window when you can apply more without scuffing. Hardness is not something I can really answer, I am of the belief that a really tough finish is a balance of hardness and flexibility so as not to crack. One thing that I really do like about WB is that the blush of solvent is next to impossible. I have never had it happen but was told it can under certain conditions. Blush happens at dew point and is moisture trapped in the finish so with WB water is the transport fluid. I can stain with 155 or 135, seal and top coat all within a couple of hours including scuffing on any average day. If you have a way to control the shop temp and humidity you can really roll.
From contributor H:
On a 70 degree day how long should parts stay on a drying rack before they could be handled or recoated? Also we are getting a lot of paint jobs with multiple layers clearcoat. We just finished all the retail casework at the World War 2 Museum and we put on three coats to produce a high gloss lacquer like finish. Can I achieve similar with WB?
From contributor C:
On the can pigmented = (9200) this is a product built on the clear = (380) which is a product for interior use. Both are recommended for use as seal coat and then top coat. Product should be applied in light to medium coats at 2-5 wet mils. Then it states, allow to dry 10-15 minutes before sanding, and then additional coats may be applied in 15 minutes. It also states you can force dry at 100deg +or- 2deg with good air movement. Now I have had very humid days when I just left the parts overnight.
But for me most times I am running a kitchen with 30-40 doors and adj shelves and 10-15 boxes plus trim and the dry time is in no way an issue. I have used the exterior grade products and they are very much the same. I have not used any exterior grade stains though. The 155 and 135 stains are spray with wipe as optional and it seems like they state dry in 15 minutes as well.
