Epoxy problem

[larcor69]

I used some new from tower hobbies 30min and no matter what it is tacky to touch, it's hard as a rock but the surface is tacky, I mixed a few cups varying the amount of the amount of hardener and it's still tacky, I am so screwed as I used it to seal the outside of a hull, now it's sand the crap out time

 

[Grimracer]

did you thin it?

 

[larcor69]

I warmed it up a bit prior to mixing, but I have made a couple of little batches and each is the same harden up well with a tacky feel to it

 

[Greg Wannamaker]

That sucks, your right though, time to remove it and start again, I switched to West Systems epoxy years ago and have never looked back. I save the 30 minute epoxies for general building and mixed in small batches. Hasn’t happened to me but you might have received a crap batch, I would toss it and buy some new. My 2 cents anyway. In the mean time, dive in and sand away!

 

[larcor69]

Yes, you are right, I have always used MAS and never a problem, I have some 15min Bob smith it's good stuff also

 

[Kez]

I have never used Tower Hobbies epoxy so I cannot comment on its properties.
Years ago, I only used Hobbypoxy 2 hour epoxy for building. It worked great. Then tried their 15 min epoxy for sheeting WOF. It cured properly but the surface remained tacky exactly like what you described. I thought I did not get the mix ratio correct but it turned out to be the epoxy. It was not a problem for sheeting foam. But applying it as a seal coat can be a problem as it will not sand well.

 

[Terry Keeley]

https://www.westsystem.com/the-105-system/

 

[Bill Gibson]

Have you tried wiping a spot on the boat with isopropol alcohol? Have you tried pushing your fingernail against the epoxy? It may be wax given off by the epoxy........not sure why you used a 30 minute epoxy for a seal coat. If the epoxy is truly cured, then you can finish sand it, and the only problem should be plugging the sand paper.

 

[larcor69]

The epoxy is hard, just tacky feel to it, been sanding away at it, it's coming off slowly, never thought of alcohol, will try that

 

[larcor69]

Lesson learned nuntheless

 

[Geraghty]

That sucks, your right though, time to remove it and start again, I switched to West Systems epoxy years ago and have never looked back. I save the 30 minute epoxies for general building and mixed in small batches. Hasn’t happened to me but you might have received a crap batch, I would toss it and buy some new. My 2 cents anyway. In the mean time, dive in and sand away!

Change to West Systems "G" Flex and you will never look back.....
Same great adhesive as standard West Systems epoxy but mixes 1 to 1 and comes in bottles like everyone else.....

 

[Daniel's Racing]

Lacquer thinner may take away the tacky and only leave the hard underneath. It works when polyester stays tacky.

Wipe the tacky off and light sand and spray 2K clear over it. Epoxy needs the UV protection anyhow.

 

[larcor69]

Thank you everyone

 

[BACKEMF]

I've had the same problem with old JB Weld but not epoxy. I've got 5 year old epoxy that is fine.

 

[Chris Thomas]

I have had the same issues with the "quick cure epoxies" staying tacky. I have learned to use only West System or MAS epoxy. West for building and framework and I like MAS for filling the grain in plywoods. The MAS penetrates the wood better, doesnt sit "on top" as much as the West System will. Not to say that the west system is not great! Stick with what works. Certain things you dont "cheap out" on.... heres some thing I've learned over the years

Do NOT be frugal with these items
1) Radio - you spend bundles of hours of building, painting, tuning and perfecting
- to see you work be eat up by a bank or weeds with a lost signal
2) Safety Equipment - 10$ head : 10$ helmet
- if you value your head; price the helmet accordingly
3) CA is NOT building adhesive. It has no strength. It is good at filling the grain of the wood and prevents the epoxy from doing so resulting with a weaker bond. Clamp the epoxy and walk away.
4) Polyester resin absorbs water. Epoxy does NOT.

 

[larcor69]

I agree with you on that, I have been a long time MAS fan, but I thought a small cheap build, a Dumas DV-10 short stuff but lesson learned, after hours sanding it, looking better now

 

[Bill Gibson]

I agree with you on that, I have been a long time MAS fan, but I thought a small cheap build, a Dumas DV-10 short stuff but lesson learned, after hours sanding it, looking better now

 

[Kris Flynn]

Change to West Systems "G" Flex and you will never look back.....
Same great adhesive as standard West Systems epoxy but mixes 1 to 1 and comes in bottles like everyone else.....

GFlex is good stuff, but man does it stink!!

 

[Nigtmare]

put it out in the sun for a day

 

[larcor69]

I did, but I still had to sand it off