Not enough hardener! What to do?

[John Kemker]

So, I had a bit of laminating to do yesterday and pulled out my Aeropoxy PR2030 resin and PH3550 hardener with a bit of 6oz. glass. Got everything setup just right, with parchment paper down on the dining room table so I didn't invoke the wrath of SWMBO, my electronic scales to measure the weight of the epoxy, mixing cups, stirrer, plastic spoons to dispense the resin and a syringe w/o needle for dispensing hardener.

Great! I'm all ready! I measure carefully, mix thoroughly, then lay down the glass and use a stirrer to help spread the epoxy evenly, wetting out the glass and squeegeeing out as much excess resin as possible.

About 4 hours later, it dawns on me: I had used only 27 parts hardener to the 200 parts resin that I had measured out. I only used half the required hardener! The part isn't tacky, but it feels "soft." The epoxy left in the mixing cup is obviously tacky when prodded with the stirrer.

Anybody got any ideas how to resolve this problem? Maybe apply a bit of heat? Or, should I just peel it off and start all over again?

 

[3stoogesrocketry]

So, I had a bit of laminating to do yesterday and pulled out my Aeropoxy PR2030 resin and PH3550 hardener with a bit of 6oz. glass. Got everything setup just right, with parchment paper down on the dining room table so I didn't invoke the wrath of SWMBO, my electronic scales to measure the weight of the epoxy, mixing cups, stirrer, plastic spoons to dispense the resin and a syringe w/o needle for dispensing hardener.

Great! I'm all ready! I measure carefully, mix thoroughly, then lay down the glass and use a stirrer to help spread the epoxy evenly, wetting out the glass and squeegeeing out as much excess resin as possible.

About 4 hours later, it dawns on me: I had used only 27 parts hardener to the 200 parts resin that I had measured out. I only used half the required hardener! The part isn't tacky, but it feels "soft." The epoxy left in the mixing cup is obviously tacky when prodded with the stirrer.

Anybody got any ideas how to resolve this problem? Maybe apply a bit of heat? Or, should I just peel it off and start all over again?

I guess it depends on the application at hand . Is the glass just to cover and reinforce a body tube , or is this a structual application ? If it is indeed needed for a structusl application , I would remove it if possible . If it is not possible , you can try a little heat , or simply re-apply a epoxy top coat.

 

[Speaknoevil]

Likely you will never achieve a full cure. I would remove it. Actually, that's a pain; I would just start over with a new airframe.

 

[Steve Shannon]

I don’t know. My understanding has always been that hardener and epoxy must be mixed in correct ratios or you end up with a portion of the mixture that won’t crosslink. That’s especially true if you use an excess of hardener; you end up with pockets of unlinked hardener. That would result in softness. But it might be different with an excess of resin. Since launching is shut down anyway you have some time to experiment. I would heat it slightly and give it a few days. If it continues to crosslink, great. If not, you will still be able to remove it.

 

[MClark]

Junk it and start over. It will never be right.
Save time and use as a learning experience.

M

 

[John Kemker]

Junking is not an option. Fortunately, the layer of glass peeled right off with a little bit of heat.

Starting all over again.