Epoxy not setting

[BobPugh]

I'm building a zip kit 26in Outrigger down to the ceiling of the boat evidently I got in a hurry on one of the sponsors and didn't get my epoxy mixture correct and it is not setting up any suggestions it's been 3 days and it's still sticky. I used 30 minute epoxy and denatured alcohol to thin the epoxy. Any suggestions thanks Bob

 

[Mike Hughes]

scrape it off and start again

 

[Hydro Junkie]

I have to agree with Mike. If it's still sticky after three days, it's not going to cure. I have seen other reasons for epoxy to not cure though they probably don't apply in your case:

• How old is your epoxy? I've seen, on occasion, older epoxy not cure. This was almost always the two part kits sold in hobby shops
• How warm is your work area? The one time I had epoxy not cure it was because it was applied and left in an unheated garage that got too cold for the epoxy to cure

 

[K F Wheeler]

I bought one of those two part kits from a hobby shop that was suppose to be 5 minuets. Started using very small portions so I could mix the two very well. I soon started calling it my 3 minuet epoxy! Some times it would start setting up before I could start applying it where I needed. As I got down maybe a 6th of the bottles it was taking longer and longer to start setting up. Taking a lot longer to get hard. Tried using more hardener but didn't seem to make much difference. Suspect that the epoxy is setting around longer before we start using it. Before we even buy it. I went and bought smaller bottles. But turn them upside down and what ever to get it to mix up. So far it's been working... I'll grab them every now and then and flip them around even when I'm not planning to use it for a few hours or even days.

 

[Mike Cathey]

Likely too much hardner to resin

 

[BobPugh]

I'm working in my basement, the temp is about 60 degrees I live Reno nv we have had some cool mornings ( the 20s ) , I think my epoxy is ok it's glueing ok I think I got the mix wrong and it didn't set up, I even tried putting the sponsons on the mantel above the wood stove with No luck.
Can you mix up good epoxy and thin it down and go over the uncured epoxy and it cure ok?? Just being lazy I guess thanks Bob.

 

[rhomodel]

No you can't, better scrape it off, so you are sure it is off. \BEcause if you have good epoxy and mix it with bad epoxy, the mixture is still wrong and it will not reach the deeper part of it. So give it a big sign and scrape... As a side note: I prefer the 24 hr epoxy: Though ittakes a while to set,the bond it creates is much stronger then any 5 and 30 min epoxy.

 

[SayMikey]

In my opinion I would not thin epoxy for gluing, I would however thin it to seal with. If you have not tried gflex by West give it a try for structural strength

 

[Anthony Asaro]

You can heat the bottles in a pan of hot water and that makes it more usable. Also I had a problem of not mixing long enough, now I mix for at least a minute and no longer have that problem you encountered.

 

[Steve White]

Something I've learned working in Aerospace for decades. Around our Material and Process engineers, they do something called "Coupon Testing" of everything.

Whenever I'm going to do something like this, test it out on scrap pieces first. Also, when using any materials - epoxy, resins, paints - always mix up enough to apply to test pieces (coupons) to ensure curing is proper along with the work.

Never open up bottles/cans of HAZMAT type materials that have lifespan requirements that are affected by time and temperature - let alone curing requirements for time/temperature/humidity and begin application without testing first.

 

[BobPugh]

Ok looks like I'm scraping it off ,so when I get it all off do I need to rub it down with assatone, denatured alcohol, nothing? And I was just sealing with the thinned epoxy , in preparation for paint.

 

[SayMikey]

Id use acetone and a single edge razor blade

 

[K F Wheeler]

I myself would use something like paper towels/shop towels, something that its self is not going to possibly add any chemicals. Acetone on the paper towels. Not enough that you would be leaving any or very little acetone behind. A last cleaning you could use a little more acetone. Other chemicals like denatured alcohol may work as well. I have a tendency to go overboard on a lot of things I do. So I like the acetone. The next step can be the hardest. The waiting for the wood to completely air out. Rush this step you could likely make things worse! Let it air out until you can't smell the alcohol at all. I might even wait an extra day. Acetone I think, would dissipate sooner. And has a smell a little more noticeable. Anyway the idea is similar to paint. You put more paint on top of other paint before it airs out you run the risk of the top coat of paint bubbling or peeling. That's my opinion... Besides, any chemical that is still present when you go to epoxy the pieces will not help the epoxy to bond and be strong as it would be by its self. Ken

 

[Hydro Junkie]

Not so sure I'd use alcohol. I know, where I work(also in aviation), we're not allowed to clean anything that will get an adhesive or sealant on it with alcohol due to the residue alcohol leaves behind. I'd stick with acetone or aliphatic naphtha to clean off the bad epoxy, along with the previously mentioned single edge razor blade.

 

[BobPugh]

So I spent most of the afternoon with rubber gloves, acetone, and a straightedge razor and I think I got all of THE UNCURED EPOXY off the one sponson I'll see what looks like tomorrow, it was nice today about 60 dogs, I had to take it down to the basement, the wife wasn't having it the house it steaks, and she was Wright, I did wipe it down with denatured alcohol, looked ok we ll see tomorrow, Thanks for the tips guys. I know one thing I will not rush my epoxy again!! Thanks again B P

 

[Grimracer]

I'm working in my basement, the temp is about 60 degrees I live Reno nv we have had some cool mornings ( the 20s ) , I think my epoxy is ok it's glueing ok I think I got the mix wrong and it didn't set up, I even tried putting the sponsons on the mantel above the wood stove with No luck.
Can you mix up good epoxy and thin it down and go over the uncured epoxy and it cure ok?? Just being lazy I guess thanks Bob.

One road in and one road out...... I have been to Reno.. best Ribs I have ever had.. the plane ride in and out is "entertaining"!

Flew helicopters for Hobbico in Reno.. love the visit.

Grim

 

[Steve White]

So I spent most of the afternoon with rubber gloves, acetone, and a straightedge razor and I think I got all of THE UNCURED EPOXY off the one sponson I'll see what looks like tomorrow, it was nice today about 60 dogs, I had to take it down to the basement, the wife wasn't having it the house it steaks, and she was Wright, I did wipe it down with denatured alcohol, looked ok we ll see tomorrow, Thanks for the tips guys. I know one thing I will not rush my epoxy again!! Thanks again B P

Test a small batch for proper curing before applying to boat.

 

[Mike Cathey]

Ok looks like I'm scraping it off ,so when I get it all off do I need to rub it down with assatone, denatured alcohol, nothing? And I was just sealing with the thinned epoxy , in preparation for paint.

If you don't take it down to bare wood the bond will be weak. Something to keep in mind when making the inevitable repairs.

 

[rhomodel]

The warmer the epoxy is, the easier it will be removed, so if you have to scrape it iff, try to warm it..
I think you did the good think going the extra effort removing the 'bad' mixed epoxy.

 

[arne kantola]

When mixing epoxy, always use paper wax free cups. I save and use my latte paper cups and buy paper cups from Aircraft Spruce. Use wood tung depresser for mixing sticks, cut them square at the bottom so to scrape up ever gram of resin. Use the 3 minute mixing rule while every 15 seconds scrape the side and the bottom of the cup. Then wipe the mixing stick off on the top edge of the cup, presoom mixing. Some aerospace company's require you to pour the mixed resin into another cup and then use.