30 minute epoxy - does it have a shelf life?

[Tim_Duggan]

I've been using Bob Smith Industries 30 minute epoxy for many years. The last thing I built with it the seams are all starting to fail. Could it be the epoxy has gone bad? I've had it for a long, long time but never had this issue before.

 

[moparbarn]

all i use too, tim. it would be a first for me, i just used some 15 min. from bob smith that has to be 6 or 7 years old. stored anywhere, even out in the garage, freezin' cold to waaay too hot.......the 30 min. never lasts that long for me, it's the mix i use the most for builds. 15 min. is more for race site repairs.

 

[Slideblues]

Timbo I was told the hardner has solvents that will evaporate if exposed to air to long.

This was back there a ways might be different with tha new stuff,

Gene

 

[Tim_Duggan]

I think I am just going to get rid of it and get some new stuff for good measure - but will buy the smaller volume ones and use them all up, more often.

 

[Slideblues]

Yup, My experience was at Motorola QC, Had to epoxy a HV pot after final test and when a bunch started failing..........

We found some operators were leaving the bottle caps off end of shift,

Gene

 

[dion smith]

I store all of my ca's and epoxys in the fridge

 

[Tim_Duggan]

From the Bob Smith website;

CA bottles can be stored in a sealed container inside the refrigerator to isolate them from moisture. Adding a desiccant (silica gel) to the container can extend the life of the CA to over four years. Opened bottles that are frequently used should not be put into into the fridge since condensation can occur inside the bottle. Accelerator should never be stored with CA.

 

[dion smith]

Good info- thanks Tim!!!

 

[Hydro Junkie]

This is what I got from a West Systems site:

Store at room temperature. Keep containers closed to prevent contamination. With

 

proper storage, resin and hardeners should remain usable for many years. After a

 

long storage,verify the metering accuracy of the pumps. Mix a small test batch to

 

assure proper curing.

 

Over time, 105 Resin will thicken slightly and will therefore require extra care

 

when mixing. Repeated freeze/thaw cycles during storage may cause crystallization

 

of 105 Resin. Warm resin to 125°F and stir to dissolve crystals. Hardener may

 

darken with age, but physical properties are not affected by color. Be aware of a

 

possible color shift if very old and new hardener are used on the same project.

 

[dion smith]

Glad my west is too big for the fridge and I have kept in a cupboard!

 

[Thomas Hulbert]

had some system 3 resin start to crystalize and was told by them ( system 3 ) to heat up in water and it will turn back into liquid.( same as honey will )

Tryed it and it worked.

Used my ulrtasonic heated cleaner.

 

[RodneyPierce]

Tim, I have also had one other experience with Bob Smith where every seam on the boat came apart. It was a disaster. I have since started using there product again, and have not had this issue... Perhaps just a bad batch/bottle of epoxy and/or hardner? Who knows, but discard and replace my friend!!

 

[Ron Jefferson]

Just took a look at my 6 minute and it's turned cloudy. Time for new stuff I guess.

 

[Tim_Duggan]

RP,

same problem here, seams failing.I bought some z-poxy 30 minute yesterday and threw out the old stuff I had. Too many dollars and hours invested for the seams to fail.

 

[Hydro Junkie]

I have never had good luck with Z-Poxy or the hobby shop varieties of epoxy. I'll pay more for West Systems and not worry about it holding than take a chance