polyurethane techniques

[jeff...]

Mike like you when it comes to kids, you can put me in the overly sensitive category. LOML and I had have 7 children and we've adopted 4. Plus we support one young girl in Uganda through compassion international, who we've never met. I still have 5 at home. Needless to say I'm either crazy or really love kids, maybe a little of both :lol:. But if you ask me, your heart is in the right place:icon_thum.

Thanks

 

[thrt15nc]

Regarding using satin for only the last coat of your finish. In the most recent issue of Wood, Bob Flexner now states that he has tested the theory that using satin on all coats might obscure the grain. He says there's no noticeable difference in the clarity of wood grain under a finish where satin was used for all coats or if gloss was used for most coats and then satin for the final. Supposedly the silica flattening agents beneath the surface of the satin finish become invisible and you don't need to worry about a cloudy look.
:-? :eusa_thin
I haven't tested this and I don't do it this way. Just passing it on.

Tom

 

[chris99z71]

(Chris, no Chinese/cat jokes, okay?)

Hey, don't look at me! :eusa_whis
You're the one who saw my cat, shouted "FOOD!" and went running after it the first time you came over!:rolf:

 

[edcox]

Hi Guys, I'm new to this site so thought I would say hello add a little to the question. There is an excellent article on water based poly's in the Nov/Dec "06 issue of Fine Woodworking. I prefer using water based products because of the low volatility and odor. I just finished a rather large shop cabinet (American Woodworker Jan "05) and using my HVLP sytem sprayed Olympic water based poly (available at Lowes). I was impressed with the clarity and ease of application. I did not thin and noticed that as it dried it kind of flowed out like lacquer. Be aware that you will have to sand lightly after the first coat when using water based products as they will raise the grain slightly. Although I applied three coats and sanded between each I'm not sure all that sanding was necessary.
I'm sure I'll be checking in from time to time to get some other answers from all the experts. Good luck

 

[woodguy1975]

Regarding using satin for only the last coat of your finish. In the most recent issue of Wood, Bob Flexner now states that he has tested the theory that using satin on all coats might obscure the grain. He says there's no noticeable difference in the clarity of wood grain under a finish where satin was used for all coats or if gloss was used for most coats and then satin for the final. Supposedly the silica flattening agents beneath the surface of the satin finish become invisible and you don't need to worry about a cloudy look.
:-? :eusa_thin
I haven't tested this and I don't do it this way. Just passing it on.

Tom

Tom, that is a good reference. I forgot about that article along this discussion. I've done the test myself side by side. Also I've done the test of rubbing a satin to a gloss and compared to a gloss rubbed out to a gloss. Again there was no significant difference to me.

 

[woodguy1975]

Hi Guys, I'm new to this site so thought I would say hello add a little to the question. There is an excellent article on water based poly's in the Nov/Dec "06 issue of Fine Woodworking. I prefer using water based products because of the low volatility and odor. I just finished a rather large shop cabinet (American Woodworker Jan "05) and using my HVLP sytem sprayed Olympic water based poly (available at Lowes). I was impressed with the clarity and ease of application. I did not thin and noticed that as it dried it kind of flowed out like lacquer. Be aware that you will have to sand lightly after the first coat when using water based products as they will raise the grain slightly. Although I applied three coats and sanded between each I'm not sure all that sanding was necessary.
I'm sure I'll be checking in from time to time to get some other answers from all the experts. Good luck

Spraying water based products is a whole new world. It is tough to spray verticle surfaces with WB finishes and not get runs. I can pour it on with my solvent based products, but have to cut the surface film thickness in half with WB products to get good results.

John

 

[Gofor]

Here is an example of 3 coats satin poly (minwax) polished out:

The drawer side is spray lacquer but the rest is oil based poly.

 

[OriginalChong]

Question, if this particular polyurethane is water based, that means it's water soluble. How well does it hold up to water? I mean, you wipe it with a damp cloth, some polyurethane gets taken out. You apply a coat on wood, the wood is not affected because you just applied a coat of water-based product on it. Just curious. I'm sure the developers of the materials know what they are doing but I'm concerned about using water-based products on furniture. It's like using water-based products on leather. Ultimately, it dries it out.

Show me your wisdom:icon_bigs

 

[DaveO]

From what I have read. Water based ployurethane is more a water borne oil modified polyurethane or basically a latex paint without pigment. Latex paint is water based and cleans up with water, but once cured can be scrubbed with water without removing any of the paint. Water isn't as much the solvent as it is the vehicle. There is still a chemical curing reaction that takes place just like oil based poly.
I think :icon_scra

Dave

 

[chris99z71]

From what I understand, DaveO is right on.
Here's a thread on sawmillcreek along the same lines that gets a little more into the chemistry. I found it to be interesting reading:
Poly? Urethane? Polyurethane? - Sawmill Creek

And here's another "chemistry intensive" article from PWW, this one does the best job I've seen at explaining the different classes of finishes at a molecular level:
Popular Woodworking Magazinehttp://www.popularwoodworking.com/features/fea.asp?id=1094