Waterborne Finishes - Pros and Cons
Here's a long thread with finishers comparing the attributes of waterborne finishes to solventborne products. May 27, 2014
Question
What are all the pros and cons of water base finishing? What is the cost difference? What are the health differences as far as application and offgassing? What is the equipment difference compared to solvent? What PPE is required during application? What are the environmental differences during application? Same booth required, same temperature, etc.?
Forum Responses
(Finishing Forum)
From contributor J:
Pros:
far fewer fumes and harsh off-gassing
water clean up
fewer onsite hazards
ideal for doing green builds
it is the way of the future, so get on board
Cons:
if you do not have forced heat or an oven, dry times are longer in cool to cold weather
imparts less life to the wood
requires one extra sanding step to get the same quality finish
pricing seems to be towards the higher end of the spectrum
From contributor N:
I spray about a 50/50 mix of solvent and WB. I pay just over $40 for my solvent CV and $55 for my WB CV.
The solvent CV I use (Rudd) outgasses for days. When I go into the shop the morning after a big solvent CV day, the first thing I do is turn on the booth exhaust fan and I wear my respirator in the drying room for a whole day after spraying. For the WB the first thing I do is, turn on the compressor... little to no odor.
I use an AAA unit or a gravity gun (small jobs) for solvent finishes. I prefer to use a pot and gun for WB finishes - works better for me than my AAA unit, better quality finish (lays down better) and little to no micro-bubbling (the bane of waterborne). I spray it in the same booth as the solvent finishes and I wear a respirator while spraying.
Both finishes like it warm to very warm but the WB CV is more lower temp tolerant (it will dry at 55 degrees, just a lot slower) than the solvent CV (needs heat to polymerize), but not as tolerant as solvent lacquer.
WB needs through sanding and dusting and a clean booth and drying room. For some reason every speck of dust shows up on it - completely frustrating. I apply 3 coats of solvent CV as my standard new cabinet finish (self-seal plus 2). For the WB it's sealer plus 3 coats of finish to achieve somewhat the look, feel and build of the solvent (still not quite as nice).
For pigmented jobs I've switched over to WB for 9 jobs out of 10 - primer, two coats of WB lacquer and a top coat of WB clear poly. Beautiful finish if not quite as durable as solvent pigmented CV.
I make quite a bit more money using the solvent stuff. It's a lot easier, but I could live with going all WB and be happy about it.
From contributor P:
Probably one of the biggest challenges to going totally WB is getting used to a different stain system. Shorter open times with WB wiping stains is a real challenge, as is getting the same colors, consistency and clarity that you may be used to. I try to be totally WB, but for certain woods like oak I still use oil-based stain. The other comments are on the mark. Another thing is that WB might be more sensitive to high/low humidity ranges.
From contributor J:
Waterbornes like everything to be perfect, 70-80 degrees with 70% humidity and dust free air. High humidity will not make it blush like a solvent finish, though. Really low humidity can cause it to not flow out as well. Large amounts of sanding dust will not melt back into the finish when you spray the next coat, so you have to vacuum really well. You can't hose on thick coats, especially on vertical surfaces. WBs do not hang well on vertical surfaces and there is a very fine line between too much and not enough. I actually have found that my airless (Titan 440i with a 308 or 312 Graco racx fine finish tip) will lay out a flatter finish than my pot and gun set up (Asturo Eco ssp with a 1.3 tip set), but I save a bit of material using the pressure pot and it's more controlled on smaller parts and for spraying on WB wiping stain. As far as forced drying/curing for my setup, I decided to go with heated forced air in a drying room. I tried IR curing lights but they didn't address the problem of high humidity and used a lot of electricity. I will still use them to cure a single panel/door or other small repair.
From contributor N:
Contributors P and J, what water based wiping stains are you guys using?
From contributor A:
- Pros -
1. Routine cleanup of uncured material only requires soap/water, followed by a final rinse of denatured alcohol which can be reused for a long time.
Don't let the easy initial cleanup fool you into letting things harden up, because then it won't be so simple. As the durability of some waterborne finishes is getting to be pretty good, anything that sets up in/on gun parts, especially for more than a week, will need to be softened with something stronger, like acetone, and even still getting it off can be a pain.
2. With many WB products you can build up numerous coats without worrying about staying within dry film limitations of 4-5 mils common to many solvent systems. That extra coat or three, won't be an issue. Schedules for many more exist and the side effects if done right are typically limited to slower final cure.
3. Also many WB product lines (especially Target coatings) have numerous stains, sealers, and top coats to choose from, all of which are compatible with each other. I feel that this, along with not having to worry about dry film so much, gives you options to break out of the mold of applying the same approved sealer along with the same 2-3 coats of whatever post cat clear.
4. Being able to deliver parts as soon as the same day with little to no detectible off gassing/odor has been a lifesaver. Before my shop would get bogged down for a week or more waiting for stuff to cure.
Just the other day I sprayed 3 final coats on a cherry assembly, the last 2 being cross linked Target em2000 sprayed heavy. I was confident that it was dry enough to load in my truck, and strap down with minimal protection, just 30 minutes after spraying the last coat. It does help that it was 80 degrees.
A while back, I had to re-finish a refrigerator panel that had been damaged in my shop. Sprayed a dye stain and toner that evening, and then managed to spray a coat of sealer, followed by 3 topcoats the next day. Got it ready to deliver, and install that evening. Client could not detect odor or off-gassing.
- Cons -
1. Grain raising generally requires extra sanding. This varies depending on a couple of factors.
2. Waterbornes are not particularly forgiving when it comes to sub-par setup/equipment and bad technique. Don't expect dry overspray to melt into a film.
3. Adding cross linker/catalyst generally requires more care. Can't just dump it in and mix. Have to add and stir slowly, and in some cases allow 1+ hours before it is ready to use. The good part is that catalyzed material can often be used for a week, or more.
- Neutral -
1. Durability. I have heard arguments for and against waterborne, and often durability is a concern. That said, I have seen lower quality waterbornes (especially the oldest formulations) fail badly. Then again, I have also seen solvent coatings in the field that were done by others, that have failed miserably.
Like most I have my doubts as far as durability, however since I have been working with waterbornes, they have held up well in my experience, and I am gaining confidence in their durability. Have not had any problems yet.
2. Appearance wise, the ultimate clarity of some solvent coatings seems to be a little better for the time being.
I am well aware of the typical complaints that waterbornes lack warmth. Whatever. I have seen some formulations that do look awful. After 2 years of trial/error I am getting some results from waterborne that I am quite pleased with. Especially on woods like cherry, and some extra steps/hybrid methods are involved. Getting results out of solvent systems that are better than average takes extra work as well. You will need to learn new tricks. That does take time.
From contributor P:
I use mostly General Finishes and Target WB stains.
From contributor J:
I now use General Finishes exclusively. I used to use Target Coatings but was unable to economically stock everything I needed, as they are in New Jersey and I am in California. Shipping times and extra costs became a factor. Target's WB linseed oil stain is really good looking and solves most of the lifeless problems associated with WBs. The down side is it acts like an oil stain and can be slow to cure, especially if the batch is on the older side. General are not oil base, so you can really stick the heat to it and get it dried in a hurry. They are a little more muddy and rely on a topcoat that ambers to give them their life and depth. That said, none of my clients have seemed to care or notice the difference. Target's products do not build as quickly as a comparable product from General.
From contributor J:
The statement that WBs do not have dry mil limitations is not completely true. It depends on what brand you are using. For instance, Valspar's Zenith line has a strict dry mill limit and it will crackle if you go over it (my sole reason for not using their line). If you want to get the most for your money, you need to pick a brand that at least has semi local distribution and a complete line (stain, dyes, glaze, sanding sealer, economy and high grade topcoats, and a pigmented line that can be color matched). If you have to hunt around picking and choosing you will lose money.
From contributor N:
I'm just one state north in Oregon but I'm lucky enough that the local Miller Paint store in the small town I live in carries almost the whole Target line, just not the stain. Looks like I'll have to lobby them to carry it as well. They used to carry Valspar and you are right - their WB CV has strict mil thickness limitations, not to mention the Zenith CV is a little fussier to apply all the way around when compared to Target's CV. I'm happy and pleasantly surprised with Target's finish products - the stuff works.
From contributor A:
Note that in my comments I said "with many products," but not all, in regards to dry film thickness. Also. I never stated that a specific limit did or did not exist. Never intended to imply that either, as there are too many variables, different products, and applications to cover this effectively. It certainly is correct that there are examples that have stricter limitations than others, but when it may be desirable to use a product that is more forgiving in this regard, this is certainly a possible benefit of many WB finishes.
From contributor J:
Stain and solid colors are the hardest part of keeping a good material flow in your shop. If you can't rely on your supplier for stain and pigmented topcoats, then you need to find one that has it all, if you are doing any kind of volume. If you are a low volume, high end furniture maker that doesn't get into refinishing and matching existing colors, this is a non-issue. I do like the Target stain quite a bit.
From the original questioner:
Thanks for all the info. I am not sure what I should do? I read lots of good things about Target coatings, but like others there isn't a dealer close, so everything would have to be shipped! The two dealers I deal with carry Becker and ML Campbell. I am currently spraying Care Seal with a top coat of Fiesta. My supplier for that recommends I spray Sayerlack for a water base finish. I never even thought about all the stains? I should have been a plumber!
From contributor P:
I think the ML Campbell Agualente WB products are pretty good. It's still my go-to for pigmented (painted) finishing, and the clear version is nice, too. They have WB stain base and dyes, but I haven't tried them yet. Maybe your Campbell sales rep will give you a demo.
From contributor N:
Just one more thing - waterbornes are great for onsite finishing and refinishing.
