A tale of epoxy resin, carelessness, and a "save"

[Jim Edgerly]

I have been rebuilding my doors on The Schnoodle Shack as those familiar with my build journal already know. I fitted them to The Shack, stained them, and was now ready to start the finish process. I used Raka epoxy resin on The Shack back in September, and I am very pleased with the results. Easy to work with, nice finish. Well, I placed my doors in a convenient to work location in my workshop, pumped 3 ounces of part A (resin) and 3 ounces of part B (hardener) into my container and started mixing, for 2 minutes as recommended in the manual. Those familiar with Raka already know the problem. The temps in my basement are a bit cooler than outside in Sept, so the consistency is closer to a "nectar" than the varnish consistency it was in the warmer temps, but no problem, I can still spread it OK. So I completely finish the first door, and I go to mix more for the second door...and the realization of what I had done hits me in the gut like a sledgehammer. I see how much lower the resin is in jug A than the hardener is in jug B...because you use TWICE as much resin than you do hardener for a proper mixture! I had carelessly mixed it 1:1 instead of 2:1. I immediately ran upstairs and called the Raka sales line.

I talked to Larry, who answered on the 3rd ring. I asked him if I had just ruined my project, and he didn't answer with a yes or no. What he did tell me was that the epoxy resin as mixed would never totally harden, and that it would always remain "rubbery". He asked how long since I put it on and when I told him just a few minutes since I finished he told me my best bet was to go down and scrape off as much as I could as fast and I could, and wipe down the door with acetone or varnish thinner afterwards, and sand off what I could not remove.

60 seconds later I had grabbed a handful of rags, an assortment of plastic putty knives, and was pulling on my disposable vinyl gloves. I thanked God for the cooler basement temp because the epoxy resin was still the consistency of nectar and had not even begun to cure, and the scraping process was not too bad. I placed a large piece of cardboard under the window "hole" where the window will go, and started scraping all the resin into the hole onto the cardboard (the door was already lifted off the table on blocks). Once I had as much scraped off as possible, I started the varnish thinner wash. I took an empty plastic margarine tub, put an inch deep of varnish thinner, and used half of a steel wool pad. I soaked the pad, wiped it over the door, then kept rinsing it out in the thinner and re-wiping the door. I changed the thinner a couple of times so as not to reapply a thin coat of resin, and after about 15 minutes of cleaning the door it appeared pretty clean. I then soaked a couple rags and wiped down the doors to get any remaining residue off. Luckily the thinner evaporates pretty fast, and after a couple of hours I recoated the door with the properly mixed epoxy resin. The door appears to be fine, but I swear my heart skipped a few beats once I realized what I had done.

I learned the soaking steel wool pad in thinner/varnish remover years ago from refinishing a table. I'm glad I remember it under pressure, and I hope someone else in here can use it in an emergency, that's why I'm posting this under General Discussion instead of just my build journal.

[aggie79]

Jim,

Thank you for sharing your experience and technique. I had not known about the thinner/varnish remover method. It's good to know that it works on epoxy.

We have a couple of pieces of furniture waiting for me to re-finish. Since I have expressed my dislike of finishing wood many times, it easy to see why I've put off re-finishing these. Now, though, I may give it a try as a winter - or at least a Texas version of winter - project.

Take care,
Tom

[Jim Edgerly]

Hi Tom,

Years ago (around 30 years now) I used "Homer Formby's Furniture Refinisher" to refinish a table. Formby's dissolves the hard varnish and the steel wool soaks up the dissolved finish and lifts it off your project, as I discribed. I have no idea if varnish thinner would dissolve old finish, but I swear by Formby's furniture refinisher! They also make a product for polyurethane. Here is the link to their home page http://www.formbys.com/products/ The nice thing about Formby's is it dissolves the varnish, but the stain and patina underneath remain untouched.

I would imagine that cured hardened resin would not be successful like the uncured resin was. I was lucky to get to it so fast. If I had mixed enough epoxy resin to do both doors upfront then I would not have noticed the problem until it was way too late to fix! You can't scrape off "rubber", nor can you sand it off.

take care, Jim

[Larry C]

White vinegar also works good to destroy uncured epoxy. It's safer to use than the nasty chemicals like acetone or lacquer thinner. It might not have been the best choice for your situation, but it does work quite well. It's how I clean tools with epoxy on them.

Larry C

[doug hodder]

Doesn't Raka have a metered pump system? The West system is 1 pump of resin...1 pump of catalyst, the pump bodies meter the correct amount. Doug

[LarryJ]

Doesn't Raka have a metered pump system? The West system is 1 pump of resin...1 pump of catalyst, the pump bodies meter the correct amount. Doug

It does - he only pumped once for each - he was supposed to pump twice for one of them. The kind of mistake I am good at

Good tip to know to fix it though

[Jim Edgerly]

The pumps work fine! I can count to 1 and 1...and I can count to 1 and 2...it is just a matter or remembering to count to 2 that was the issue...hence the "carelessness" part of the subject. Raka did everything correctly, and if I could say the same about me you would have read an entirely different story.

[Jim Edgerly]

WOW, I just realized how the mantras at the bottom of my pages for the last year are all coming true.

*When doing anything, if there exists no possibility of failure... then something is wrong
** The glass is neither half full nor half empty...it's just that I only put half the resin in the pot
***If at first you don't succeed... then everything is going according to plan
****When I die... I will probably wake up the next morning dead

If we can't laugh at our own mistakes then we are not justified in laughing with others!

[iSpy]

..................................


..... did you manage to chatch problem this on camera ????

[Jim Edgerly]

iSpy, Nope, I was too busy running around like a fool with flubber drying on my door to try to capture any of my "3 Stooges moment" on film.

[starleen2]

Thank goodness you caught it in time - nothing is worse than cleaning up a gooey mess!

[Miriam C.]

I am confused: If the pump automatically regulates the correct amount is one pump twice as much or do you really need to pump twice Need to know cause I am epoxying mine when I get a chance to build it back..

[justageorgiaguy]

I am equally confused - wouldn't your mixture just cure faster? you basically had twice the amount of hardner needed. Maybe not, but I just think of the 2 part epoxies you get in those little syringes and Bondo where it just creates more heat and dries faster...

[Jim Edgerly]

Dear Confused in MO...with the Raka system you mix 2 parts of resin with 1 part of hardener to make your epoxy resin. The pumps dispense one ounce of fluid per pump. So if you want 3 ounces of epoxy resin you mix 1 ounce of hardener to 2 ounces of resin. If you want to make 6 ounces of epoxy resin you mix 2 ounces of hardener to 4 ounces of resin...1 pump equals 1 ounce.

My mistake was not remembering the 2:1 mix ratio, and to make 6 ounces of epoxy resin I mixed 3 ounces of hardener to 3 ounces of resin. Larry, at Raka, said that would never harden and would be rubbery... hence my use of the word FLUBBER.

Now, the next logical question is, does the manual say to use 2:1 mix ratio...of course it does. Does the bottle say to use a 2:1 mix ratio...of course it does. Do I have 2 bottles of resin and only 1 bottle of hardener...of course I do. And in September having never used epoxy resin before, and scared to death of ruining my teardrop, I read the manual multiple times before ever ordering the stuff, and again right before using it.

Now, let me tell you something about men. If we have done something before, even if it was only once before, we sure as heck ain't going to read no stinking manual before doing it again. That would be so...so girly, if you catch my drift. I have broken the men's code of silence by admitting this, so let's just keep it between the two of us...OK, and we won't speak of this little factoid again.

I guess I should add "haste makes waste" to my mantras at the bottom of my posts, but I won't.

Have a nice day.

[Jim Edgerly]

James in GA: I'm not a chemist (I opted for a second physics course in HS instead), but I do know that stuff like this where you add two stuffs together to make something different, then you really need to follow the directions. The bottle clearly states that adding extra hardener will only make for a soft cured epoxy. The manual also states "I want to emphasize the importance of proper mixing. Epoxies strength and desirable properties come from the complete mating of the resin and hardener molecules in the correct ratio. Too little hardener produces brittleness, and too much hardener makes your epoxy softer with the accompanying loss of strength. If you make an error, you're safer to use a little less hardener, than too much."

Here's an example of why proper mixing is important in chemistry...H2O is water, which tastes really good. Adding an extra oxygen molecule, H2O2, does not make the water any wetter or taste any better, in fact it would make it Hydrogen Peroxide (hydrogen dioxide), which doesn't taste nearly as good!

If you take anything away from this it should be...FOLLOW DIRECTIONS