Q? about West Systems epoxy

[er9]

i have very limited experience with West Systems epoxy so need a confirmation.

in desperation recently bought a qt of 105 resin and 206 hardener. mixed them 1 to 1 per instructions and mixed thoroughly for a minut or two before pouring.

used it to fill 3/4 wide x 1" deep holes on my deck. ambient temp was 75+ degrees in warm SoCal. none of the resin cured past a gooey to rubbery consistency. thinking maybe i did something wrong i repeated the test at work on a hot 80degree day. same results. after two weeks its still soft and rubbery.

is the 206 capable of curing solid under these circumstances/amount or should i have used the fast cure 205?

From my resin experience im guessing the 206 hardener i bought is bad. it should have cured since they claim it as a laminating epoxy. i'm really reluctant to waste another $50 on crappy hardener but i would really love to finish this job this weekend so i'll wait for some feedback. maybe the 206 was a bad choice?

[rbk]

105 resin and 206 hardener. mixed them 1 to 1 per instructions

Re-read the instructions. It should be 5:1. Too much catalyst to resin leaving extra catalyst. Unless you were using the pumps then yes it is 1 pump to 1 pump BUT you need to make sure you have the right pump for the right hardener.

You should also add some filler to this for a hole that size or it will most likely crack.

[BigNut]

Get the pumps. Absolutely worth it.

[Lepke]

Shoulda been 5:1, resin to hardener by volume or weight. I'm reading the instructions off the quart can. It's worth having the pumps or a scale to ensure the mixture. I would have thought with 1:1 mix, it would have cured in the mixing bowl.

If it hasn't cured by now, dig it out and mix a proper batch. The new batch should cure what's left in the holes.

West Systems is my favorite, I never had old resin or hardener fail to cure. But if I knew it was old wouldn't use it except as a filler. I use to buy resin in drums.
Hardener turns a dark orange color when old. There should be a lot number on the can. Contact West. If you bought the resin/hardener at a marine store, it may have sat for a long time - they're so overpriced.

[er9]

ugh!!! you guys are correct. i misread the instructions. cant believe i did that. i know better.

thanks for pointing it out.

i will do another test at 5:1 and see what happens. hardener is light amber color so its probably just fine.

[roverhi]

The pumps cost about $20 and money well spent. One pump catalyst into 1 pump resin and mix. No messing with measuring cups, possibly spilling either catalyst or resin. As you found out resin/catalyst ratio is crucial with epoxy. If it was polyester resin just would've gone off really really fast.

[Wotname]

Originally Posted by er9

ugh!!! you guys are correct. i misread the instructions. cant believe i did that. i know better.

thanks for pointing it out.

i will do another test at 5:1 and see what happens. hardener is light amber color so its probably just fine.

Now you got that sorted the following maybe helpful.

The resin will cure faster in higher ambient temperatures.
The resin will cure faster when exposed to UV i.e. when using outdoors in the sun.
The resin will cure faster when used in larger volumes i.e. small exposed surface area.

You job sounds like all the above factors will apply so be prepared for a faster curing time than expected.

[double u]

“I would have thought with 1:1 mix, it would have cured in the mixing bowl.“

Thats not the way epoxy works.
If you mix a 5:1 system 1:1 4 parts hardener get “left over“ & don't “participate“ in the reaction, resulting in a soft or tacky endproduct. I am amazed it cured at all.
There are some epoxy sytems (long time ago I used such a system from Ciba Geigy) where a slight (!) variation in the proportions is possible, more hardener resulting in a more fle.xible, less weather/water resistant result & slightly less hardener resulting in a more rigid & more durable glueline.

[MicHughV]

I built my first boat back in the late 70's and was introduced to the West System by another boat builder. At that time, it was the glue de jour, the best of the best.Together with the epoxy, it came with a variety of fillers. There was practically nothing that one could not do with this stuff. While I used the West system primarily for interior wood components, three other builders I knew at the time were building entire boats with this stuff. All of them trimarans, which was very much in vogue back then.

Once something was glued together with this glue it was pretty much a permanent bond. I used the pumps that screwed right on the hardener and epoxy container. Never once had a problem with them. When mixing small amounts, I would depress the pumps very slowly and count the drops and never had a problem doing that either as long as I maintained the correct ratio.

West Marine was not around at that time, so I ordered mine thru' the " Defender" Marine" catalog as I recall. Defender is still in business today and typically have much better prices than West Marine.

I believe you can order the West System product through Amazon as well.

Since the late 70's, there are now other similar style glues on the market, though I'm not so familiar with them, but it would be a good exercise to shop around.

West Marine sells these little packets of epoxy and hardener for small projects, probably about a tablespoon amount. Very handy to keep on your boat to fix the odd thing that needs fixing. However, walking into a West Marine store typically requires you take out a loan from your bank first.

However, one caveat about these packets. I finally got to use them, after sitting in some locker forever. How long ?...I can't remember....but long.
Both the epoxy and hardener had discolored and simply would not form a good bond. The bonded joint would remain wet for several days vs. the hour or so it usually takes. I made repeated efforts with these little packets, but the result was always the same.

Reluctantly, I threw the remaining packets away and purchased new one's and had better results. I've heard various arguments about the shelf life of this product, but from my perspective, this product does have a shelf life. How long ? I could not say, but if one notes the product has discolored, a red flag should go up and I would recommend doing a trial run first.

Other than my experience with the old packets, I would consider this an amazing product as it can be used in a wide variety of ways.

[coopec43]

I haven't read all the comments above thoroughly but has anyone commented on your statement " and mixed thoroughly for a minut or two before pouring'.

Yours' could be a different epoxy to the ones I've used but I would always allow the epoxy/hardener to "sit" for at least 10 minutes before using.

Please read the instructions though!!

[MicHughV]

The West System glue is a chemical reaction between the epoxy and hardener.

In my experience it is very temperature and container size sensitive.

On a hot day, I have had this epoxy start to go off and get hard in the mixing container minutes after I mixed it. It would start smoking and get very hot using a small cup-like container. Within 5 minutes, it had set up and became unusable.

Typically, I would begin using it as soon as I mixed it.

Conversely, on a cold winters day, the product seems to get dense and hard to pump. One has more time in the winter.

Regardless, I would advise using this product as soon as it is mixed.

[dfelsent]

West sells slow hardeners for use at elevated temperatures. This helps avoid the desperate rush.
West has excellent instructions and application notes. They describe pot life for various hardeners at different temperatures. They are well worth reading.

[MicHughV]

yes, you are correct....forgot to tell about the slow and quick hardeners...and yes, West provides excellent " how to" instruction notes...

...It's good stuff, but one needs to learn a bit about all the additives, mixtures, etc...takes a while to get to know all the inn's and out's of this product.

...if you are building a boat you will have time to figure it all out, but if this is a one time usage, one may not get to know all the intricacies of this product, though reading the instruction notes will go a long way to avoid screwups.

[US1Fountain]

Used to use West System yrs ago because of the ease. I now buy my epoxy or VE from US Composites about for 1/2 the cost, plus they carry everything else needed to do glass work.
You can also put your mixed resin in a larger pan so it’s not in a ‘bucket’ for a longer working time.

[Group9]

Originally Posted by BigNut

Get the pumps. Absolutely worth it.

Yep, best thing about the West System. It's almost impossible to mess up the mixing ratio with the pumps.

I say almost because it is possible to put the wrong pump in the wrong can under certain circumstances, so read the instructions and proceed accordingly.