4200 shelf life

[fred1diver]

hey everyone, I bought a tube of 4200 about 3 months ago but now it's all cured inside the tube, what is the normal shelf life of this product?
any tips to prolong it's shelf life?
thanks in advance

 

[Roland5048]

what is the normal shelf life of this product?

Almost indefinite...until you open it.

 

[fred1diver]

ok so what is the shelf life after you open it?

 

[Ralph Johnstone]

Almost indefinite...until you open it.

Exactly.

You can maybe, with clean living, good nutrition, and a positive attitude towards life, get a few more months of life by storing the 4200 in a baggie in the refrigerator. But don't bet the bank on it.

 

[Roland5048]

ok so what is the shelf life after you open it?

In my experience, it's the time it takes for you to use what you need at that moment. No, seriously, I've heard about putting it in the freezer but haven't actually tried that.

 

[Jake N Eggs]

Seal it up in a food saver after use. Best done when the admiral is not at home.

 

[Ilanortho]

Ace hardware and others sell an orange plastic device that looks like a long twig that tapers at the top into what looks like a unibit drill. You cut it to length depending on how much is used up in the tube and shove it down the nozzle into the cartridge and the top firmly screws into (not onto) the nozzle tip expanding it a bit and effectively sealing it leaving very little dead space. Can be reused. Only $2. I have kept 4000 UV tubes viable for 2 months; don't have longer experience but were like new. Can't see anything possibly being more effective

 

[Roland5048]

I'm getting ready, soon, to open a new tube of 4200. Thanks for that tip. For $2, it's worth a shot.

 

[Charlie Jones s/v Tehani]

Store 4200 and 5200 in the veggie drawer in frig. I've kept both that way for months

 

[CloudDiver]

I've had that problem on a squeeze tube of 4200 I opened a while back. I cut it open and found only the forward portion cured. I used what I needed and tossed the rest, I got the tube free anyway... In general keep them stored in a 'cool' place and out of the light; if your garage or shop gets too hot, move them inside the house into a closet or something.
I like the Ace Hardware orange plastic device suggestion, I'm going to get some of those. I have to open a tube of DOW 795 and use just a small bit before proceeding with the rest of my window job, so I'm really in need of something that will ensure the rest of the tube isn't wasted. P.S., since Dow 795 is a silicone, moisture actually makes it cure faster. Hence I am reluctant to put it into the fridge!

 

[Charlie Jones s/v Tehani]

Ace hardware and others sell an orange plastic device that looks like a long twig that tapers at the top into what looks like a unibit drill. You cut it to length depending on how much is used up in the tube and shove it down the nozzle into the cartridge and the top firmly screws into (not onto) the nozzle tip expanding it a bit and effectively sealing it leaving very little dead space. Can be reused. Only $2. I have kept 4000 UV tubes viable for 2 months; don't have longer experience but were like new. Can't see anything possibly being more effective

Large nail does the same

 

[justsomeguy]

There's some good 4200 somewhere in that tube. Depends on your willingness to get a bit on your fingers, but there's some in there.

 

[Ralph Johnstone]

I have to open a tube of DOW 795 and use just a small bit before proceeding with the rest of my window job, so I'm really in need of something that will ensure the rest of the tube isn't wasted.

I've had a cartridge of 795 in a Ziploc bag in the fridge for a year now. Used some recently and found it to be almost uncured at the tip which was plugged by a #10 wood screw. Well past the expiry date but no noticeable problems.

I was trying an idea I had seen recently as to whether new 795 will stick to old cured 795 and yes ............. like sh!t to a blanket, to put it technically.

 

[CloudDiver]

I've had a cartridge of 795 in a Ziploc bag in the fridge for a year now. Used some recently and found it to be almost uncured at the tip which was plugged by a #10 wood screw. Well past the expiry date but no noticeable problems.

I was trying an idea I had seen recently as to whether new 795 will stick to old cured 795 and yes ............. like sh!t to a blanket, to put it technically.

Thats good news... Basically what I am doing is knifing on a thin layer of 795 to the mounting surfaces of my new windows instead of using black paint. I'm not so certain of the peel strength that paint would have. I'm doing that so when I use the 3M high-bond tape to mount the windows you won't be able to see the tape through the pane. After they are securely mounted with tape I'll caulk the 795 around the outside and inside edge, and the tape creates a nice stand-off to maintain film thickness.

 

[JamesG161]

what is the normal shelf life of this product?
any tips to prolong it's shelf life?

You might want to check out this link...
http://forums.sailboatowners.com/index.php?threads/dow-795-alternate.178186/page-2

Most adhesives contain a solvent or Drying agent ( once dried it is cured). Your tube should have a date for shelf life on it.
Your unopened tube can have an expired shelf life and still be in a usable state.
These dates are field tested in a remote Mom Pop hardware store in the Arizona desert.

All of the tips above are good, but one, not so much.

Use of a vacuum sealer will actually increase the rate of loss of the drying agent. A double ziplock in a cool environment will work best by pushing out as much air as you can before Zipping up. Every time you open and close that Ziplock you lose some "drying agent".

Freezing a tube may affects certain types of adhesives negatively.
Jim...

Tip: When you buy a new tube for future use, go ahead and treat it like it was already opened. That will extend the shelf life.

 

[Ralph Johnstone]

Basically what I am doing is knifing on a thin layer of 795 to the mounting surfaces of my new windows instead of using black paint.

Nice idea.

I've got to admit that I wasn't tooooooooooo sure as to how the new 795 would stick to the old 795 but it was as good as what the old 795 was sticking to the acrylic sample I had laying around the shop. I take it your not covering the surface (with 795) where the tape is being applied. Not too sure how OTHER adhesives will stick to 795.
Could you please photo your work and publish here as I am collecting the best ideas of how to replace fixed ports as I gear up for this winter or the next. Every so often you see a new idea in port replacement and yours is definitely a good one.

 

[CloudDiver]

Nice idea.

I've got to admit that I wasn't tooooooooooo sure as to how the new 795 would stick to the old 795 but it was as good as what the old 795 was sticking to the acrylic sample I had laying around the shop. I take it your not covering the surface (with 795) where the tape is being applied. Not too sure how OTHER adhesives will stick to 795.
Could you please photo your work and publish here as I am collecting the best ideas of how to replace fixed ports as I gear up for this winter or the next. Every so often you see a new idea in port replacement and yours is definitely a good one.

Ralph, will do... I have a thread going the restoration of my C-22 and I will post there. I got the idea from collecting as much info as I could on window replacement and also how its done on new boats at the factory. I also paid close attention to the tech data sheets for both DOW 795 and the 3M VHB (Very High Bond) tape. The 3M tape is used to mount heavy glass panes on buildings so I'm very confident it will do the job. This method is all based around not using screws in the installation process.

 

[Ralph Johnstone]

I also paid close attention to the tech data sheets for both DOW 795 and the 3M VHB (Very High Bond) tape.

Have you ever come across any literature on UV effects on 3M VHB tape. I know that silica glass (window glass) is a good screen for UV but acrylic is not. Wonder if you get any degradation in time under the acrylic. If that's the case, you may want to use a narrow strip of 3M VHB tape to position and act as a stand off for the acrylic, and rely more on the 795 for mechanical adhesion. I have GOT to get a handle on my OCD.

Did you ever see this video ? The best I've seen for fixed port installation. Most others are bad to completely useless.

http://boatworkstoday.com/archives/1735

This guy is so good in his setup and yet he completely missed using blocks of wood glued in place with hot-glue in order to exactly position the acrylic before dropping it on the 3M VHB.

I'll be checking on your restoration for further ideas on port replacement.

 

[CloudDiver]

Have you ever come across any literature on UV effects on 3M VHB tape. I know that silica glass (window glass) is a good screen for UV but acrylic is not. Wonder if you get any degradation in time under the acrylic. If that's the case, you may want to use a narrow strip of 3M VHB tape to position and act as a stand off for the acrylic, and rely more on the 795 for mechanical adhesion. I have GOT to get a handle on my OCD.

Did you ever see this video ? The best I've seen for fixed port installation. Most others are bad to completely useless.

http://boatworkstoday.com/archives/1735

This guy is so good in his setup and yet he completely missed using blocks of wood glued in place with hot-glue in order to exactly position the acrylic before dropping it on the 3M VHB.

I'll be checking on your restoration for further ideas on port replacement.

That's a great video... I've seen other videos by Andy and I think he's an awesome shipwright.
I haven't seen anything specifically regarding UV degradation for the 3M tape, but I doubt its an issue since its so widely used in architectural glass installation. The primary reason I'm painting the thin coat of 795 on the window inside flanges is so you won't see the tape through the acrylic from the outside. My 3M tape is grey where Andy's was black in that video. If UV was a problem, that coating should be enough.
The big difference between my approach and Andy's in the video... He is using the 3M tape as the primary mechanical bond and the 795 only to seal the edges. In my installation, and as you pointed out I am in fact using the narrow strip version, I'm only using the 3M tape as an installation aide. Since I really can't effectively clamp the windows to secure them while curing the 3M tape will hold the windows in place and also maintain the standoff distance. The inside mounting flange of my windows that will be touching the cabin sides is 1 1/8 inch wide, and my 3M tape in only 3/8 wide I believe. I will use painters tape to mark the alignment first, then set the windows in place with the 3M tape and use a rubber roller to apply pressure. I'll caulk the 795 round the outside and inside, but essentially most of my mechanical bond will come from the 795 vice the narrow strip of tape.

 

[Ralph Johnstone]

This method is all based around not using screws in the installation process.

Don't get too hung up on not using screws for the installation. I can say that because I've lived with installation screw holes since I got the boat new.

I've circled the holes from the factory installation and they're near invisible after the temporary screws are pulled and the holes filled with 795.