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Mislabeled MGS Hardener?


macleodm3
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I just popped open a quart can of MGS H335 fast hardener, and lo and behold, a blue liquid was in the can. All of my other H335 (fast) was a brown tint. Is anyone aware of a reformulation of fast for this system?

 

I REALLY hope that the new H335 is blue. I'm hoping that mislabeled cans is not the issue.

Andrew Anunson

I work underground and I play in the sky... no problem

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Do any of the 335 hardeners have a brown tint? All of the fast that I've used in the past had a brown tint.

Were they fresh stock? I can't speak for all epoxies (especially MGS), but the hardeners I've used will take a brownish cast once opened. Couple of months to a year. Apparently (read: I've read) it makes little difference in cure.

 

Rick

Rick Hall; MK-IV plans #1477; cozy.zggtr.org

Build status: 1-7, bits of 8-9, 10, 14 done! Working on engine/prop/avionics.
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Thanks guys, you are correct. The Fast hardener turns brown after contact with air, but its still OK to use. I guess its been a little while since I've opened a fresh can of fast. This wouldn't happen if I built faster!!

Andrew Anunson

I work underground and I play in the sky... no problem

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  • 2 months later...

I just bought my first kit of MGS335 and made the same observation described previously in this thread, but with the slow hardener. The can is labelled H340 but the stuff inside is definitely BLUE. I emailed the vendor and he tells me it's actually supposed to be GREEN. :irked:

(BTW, I did recently pass the Ishihara test for color blindness.)

 

Anybody else seeing blue H340?

 

Joe Polenek

Joe

Cozy Mk IV #1550

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If it looks green then I think you're ok, if you do have 285/287, they are *very* bright deep blue (how deep depends on the container, as it's transparent and darkens with the amount you're looking through, but it's very bright. Without some form of colour blindness interfering, I don't think it would be possible to consider 285/287 at all green.

Craig K.

Cozy IV #1457

building chapter seven!

http://www.maddyhome.com/canardpages/pages/chasingmars/index.html

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I have not seen any blue H340. It is more of a green. I can take a picture of H340 tonight if it will help.

Thanks for the offer, but I think I will just take it back to the vendor. I spoke to him on the phone today and he said that it definitely shouldn't be blue. Could be 285 hardener with an H340 label!

 

Joe Polenek

Joe

Cozy Mk IV #1550

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I read a description given by Bernard Siu in his build discussion, http://www.maddyhome.com/canardpages/pages/bsiu/index.html, as follows:

 

Epoxy Color Change (Nitrogen Contamination) Problem --

I decided to use MGS L285 epoxy system with H285F (Fast) and H287S (Slow) hardeners. I bought them from AS&S and transferred them into individual plastic containers inside the hot box (refer to hot box figure). The epoxy is light yellow in color while the hardeners are cool blue.

 

About 2 days later, the H285F hardener turned reddish brown while the H287S hardener turned to the same color at the delivery nozzle. Since I could not find any discussion on this particular hardener, I posted the question to the Cozy builder’s Group as well as the Technical Support guru of MGS from Canada.

 

It appears that the hardeners are sensitive to CO2, which will turn brown after short exposure to air. The plastic jugs I was using (above) were permeable enough for the CO2 to ‘sneak’ inside the bottles and contaminate the hardeners. Though MGS tech support from Canada feels if the epoxy and hardeners behave normally, they should be OK to use. Since I am new to this process, I certainly was not comfortable with it. Besides, they looked ugly. I decided to replace them with new ones.

 

FWIW

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Thanks for the offer, but I think I will just take it back to the vendor. I spoke to him on the phone today and he said that it definitely shouldn't be blue. Could be 285 hardener with an H340 label!

Please let us know how this turns out. thanks, Andy

Andrew Anunson

I work underground and I play in the sky... no problem

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I took my H340 (including my epoxy pump) back to the vendor today. He commented that the hardener in the plastic tubes of the pump definitely "appeared" blue. We pumped a bunch of it out into a cup and compared it to the colour of small transluscent bottles of H340 (green) and H285 (blue) off the shelf. My H340 was definitely the same colour as the other H340 and different from the H285. So I have the right stuff.

 

One thing I had noticed before, which I didn't think twice about at the time, was that when I pumped small sample amounts of the hardener into a cup (the ones that alarmed me), there were a few tiny blue speckles with concentrations of blue colour around them in the hardener, which quickly dissolved when mixed. Also, I had observed at least once, that the hardener sitting stationary in the clear tubes of my pump had areas that were darker/lighter in colour.

 

My conclusion (not knowing exactly how this stuff is manufactured) is that the blue colour that I observed may have been caused by undispersed dye in the H340. If the hardener starts off as a straw (yellow) colour, as some hardeners do, and MGS needs to make it look different, then they would add blue dye to get a green colour. If that blue dye wasn't properly dispersed, and settled to the bottom of the can, then it would be the first thing to be sucked up by the pump tube.

 

I gave the container a few good shakes and pumped it back into itself a few times, and the stuff coming out now looks homogeneous... and green.

 

Joe Polenek

Joe

Cozy Mk IV #1550

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