| Official Luthiers Forum! http://www.luthiersforum.com/forum/ |
|
| Polyurethane Lifespan http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=35175 |
Page 1 of 1 |
| Author: | Florentin [ Sun Jan 29, 2012 2:14 am ] |
| Post subject: | Polyurethane Lifespan |
I used some poly today to treat a wooden coat rack I am building. I bought the smallest container at HD, but there still is a lot left. I barely used any. What is the lifespan or shelf-life of polyurethane, especially AFTER you've opened it? Can I keep it for a while, or should I use it on some of my forms? How long can I keep it and still be able to use it? Thanks |
|
| Author: | Alex Kleon [ Sun Jan 29, 2012 4:13 am ] |
| Post subject: | Re: Polyurethane Lifespan |
I'm not sure on the lifespan, but you should pour what you need into another clean container, and work from that. If you contaminate the finish, it won't last very long. I know from experience! Don't put any remainder back in the can. You can also store the can upside down so that if a skin forms, its on the bottom. Alex |
|
| Author: | Florentin [ Sun Jan 29, 2012 9:45 am ] |
| Post subject: | Re: Polyurethane Lifespan |
Is a plastic container ok, or does it have to be metal? |
|
| Author: | woody b [ Sun Jan 29, 2012 4:22 pm ] |
| Post subject: | Re: Polyurethane Lifespan |
I don't see what would be gained by switching containers, but maybe I missed something. Oxygen is what causes polyurethane to cure. Filling the empty space in the container with an inert gas will extend the shelf life. Bloxygen is made for this. Propane works great, but propane isn't inert, it's flammable. If you've got a propane torch open the can and let propane from the un lit torch flow into the can, taking place of the oxygen. Again, remember that propane is flammable. |
|
| Author: | Alex Kleon [ Sun Jan 29, 2012 4:57 pm ] |
| Post subject: | Re: Polyurethane Lifespan |
Hi Woody - If you are brushing, you can introduce contaminents into the poly, or any other type of finish - dust, saw dust, brush cleaner residue etc. Pouring into another container will prevent this. I've had a gallon can of poly turn to gel from doing this. ![[headinwall]](./images/smilies/headbangwalluf8.gif "Mad") Alex |
|
| Author: | John Killin [ Sun Jan 29, 2012 5:40 pm ] |
| Post subject: | Re: Polyurethane Lifespan |
I just finished off a can that has been on my shelf for probably 5 or possibly 9 years depending on which project I originally bought it for. If the top of the can rim begins to rust, you might want to change containers then. Otherwise as long as you are not getting contaminates into it, you will probably be OK. |
|
| Author: | John Arnold [ Sun Jan 29, 2012 10:24 pm ] |
| Post subject: | Re: Polyurethane Lifespan |
No affiliation. http://www.bloxygen.com/ |
|
| Author: | Alain Moisan [ Mon Jan 30, 2012 9:22 pm ] |
| Post subject: | Re: Polyurethane Lifespan |
I finish all my guitars with oil base polyurethane. Since I won't go through even the smallest can for a complete guitar, I'm faced with this problem on a regular basis. The amount polyurethane I wasted because it started to cure within its container is purely shameful. Than I decided to try this: http://www.staples.com/Dust-Destroyer-D ... uct_329987 No more waste since then! |
|
| Author: | Florentin [ Tue Jan 31, 2012 2:54 pm ] |
| Post subject: | Re: Polyurethane Lifespan |
Alain, how do you use that spray with your poly? Thanks |
|
| Author: | Alain Moisan [ Tue Jan 31, 2012 9:13 pm ] |
| Post subject: | Re: Polyurethane Lifespan |
I just gently spray some gas in the can before closing it. Pretty much like you can see in the first video foufn on the blogxygen web site provided by John Arnold. |
|
| Author: | gozierdt [ Tue Jan 31, 2012 9:22 pm ] |
| Post subject: | Re: Polyurethane Lifespan |
I imagine Alain is using this the same way as Bloxygen, to eliminate oxygen from the can containing leftover finishes. I don't want to be negative, but I looked up "Dust Destroyer" on Google, and found this: http://www.inhalant.org/media/duster.html?gclid=CKGwuOHZ-60CFWkbQgodY3CbNg So it appears that most of these duster aerosols contain CFC's. I also looked up Bloxygen and found their website. Bloxygen is compressed Argon. So it's an inert gas, which won't impact the environment. I'm not castigating Alain, but even at a higher price, I'd personally prefer to use Bloxygen. I wouldn't have known the difference if I didn't investigate this thread. |
|
| Author: | Alain Moisan [ Wed Feb 01, 2012 10:29 am ] |
| Post subject: | Re: Polyurethane Lifespan |
Unless I misread, the web site you pointed us to doesn't mention anything about CFC (It says 100% safe for the ozone on the can, FWIW). It mostly warns against inhalation of the gas contained in the can. Now since anyway one should always work in a well ventilated area when finishing a guitar with poluyurethane (or most any other finish), using Dust Destroyer does not appear to me to be any much danger. Here's a quote from the web site you refered: "It is important to note, when used properly and in accordance with the directions on the can this product is completely safe and has proven to be of great value to its users." |
|
| Author: | dberkowitz [ Wed Feb 01, 2012 11:57 am ] |
| Post subject: | Re: Polyurethane Lifespan |
Most industrial finish companies put a 6-12 month maximum guarantee on the shelf life. |
|
| Author: | Florentin [ Wed Feb 01, 2012 11:59 am ] |
| Post subject: | Re: Polyurethane Lifespan |
dberkowitz wrote: Most industrial finish companies put a 6-12 month maximum guarantee on the shelf life. does that timespan include AFTER you've opened the can? |
|
| Author: | dberkowitz [ Wed Feb 01, 2012 12:13 pm ] |
| Post subject: | Re: Polyurethane Lifespan |
That depends upon the manufacturer. In one instance another builder and I noticed a problem where we tried to keep stuff fresh -- no more than four months old as we had problems if we kept it longer. |
|
| Page 1 of 1 | All times are UTC - 5 hours |
| Powered by phpBB® Forum Software © phpBB Group http://www.phpbb.com/ |
|