Clear Coat and sticky residue

JTknives

JTknives

Joined
Jun 11, 2006
Messages
8,651
I don’t know if any of you guys have had this problem but I have had it twice. I just got some system three clear coat for sealing my cordwraps. I mixed it just as told and I actually measured it on a reloading scale in grains so it was smack dab on for ratio. Thy say the mix by weight is 100:43 so I did 100 gr of resin and 43gr of hardener. I mixed it for about 5min and everything went great. I ended up making another batch in the same ratio and mixed the same amount. I used this as the last coat over the paracord. I then dabbed the excess off and let it cure for 48hrs. I kept the left over mixed epoxy right next to it. I like doing this so I can tell when things are set without having to touch things. Well this morning I started in the sheath and the wrap felt dry and good. So I washed my hands and started unwrapping the blade. The moment I grabbed the handle I could feal a slight tackyness on the cord wrap. I checked the epoxy in the container and it was rock hard. Not even a hint of stickyness even on the sides. The cord is also rock hard but it has this sticky feeling that seams to come off on your hands. It’s not bad and probably will come off of the cord with an alcohol wipe but is this normal. It feels like it is either under cured or not the right ratio. But what gets me is the cup of left over is perfect. It’s about 1/4” thick to and solid. Thanks guys for any advise or tips you got.
 
I think you want to alter that ratio to 100:50 resin to hardener, which would be 2:1.
I dunno why your bottles would have different instruction than mine..?

This is exactly what is says on my bottles: "mix BY VOLUME 2 parts clear coat resin (part A) and one part Clear Coat hardnener (part B)

So you are mixing by weight when it should be by volume.

In other words it sounds like you are a bit short on the hardener (part B) Even if your bottle does in fact tell you to mix it 100:43 by weight I would still give 2:1 by volume a shot as it can't hurt. Test it on some scrap paracord or something to make sure.

I used it on a tsukamaki wrapped knife (from nylon shoelace) I made last summer and it hardened up perfectly and the wrap is rock hard with zero tackiness and is still the same way.

I kept and still have the left over epoxy that hardened in my measuring cup which molded to all the measuring lines as I thought it was kinda cool looking :cool: It is probably around 5/8 thick and it cured over night all the way through as well.

I just filled up a mixing cup to 10 ML with resin and then brought it up to the 15 ML line with hardener. Hope this helps.




(edited for typos and for clarity)

~Paul
My Youtube Channel
... (It's been a few years since my last upload)
 
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Yes by volume it’s 100:50 but by weight it’s 100:43 because the hardener weighs more per volume then the resin. This is right off there web site.
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I was wondering if that was what the volume converted to in weight.

Maybe it would still work better if you measured by volume? lol

I don't know, sorry I can't help more but it worked great for me when I used it.

~Paul
My Youtube Channel
... (It's been a few years since my last upload)
 
The weight measurement is more accurate, so you did right there - 100:43.

I have found cold temperatures and high humidity can leave a slight tackiness on finishing thin clear resins.

What I do is wipe the handle down well with denatured alcohol (NOT acetone) and set aside for a day in a warn dry place. It has always been fine after that.
 
Jt
Nomally I would say to stick the entire knife in the oven at 150°f for an hour or two. This will cause the epoxy to harden more. Each thermal cycle will make it a little harder. BUT, I repeat BUT since I don't know the working temperature of the cord you used, I suggest starting with an hour at 130°f and go from there.
Jim
 
Yeah i was starting to think it might just not have been cured all the way. I coated it Monday at 4:30pm so 72hrs would be Thursday at 4:30pm. Thy say tack free at 48hrs which would of been yesterday at 4:30. But this is at a temp of 77°. I keep my house at 71° in the day and 69° at night so maybe it’s ok. I will check it in a little bit and see how it is. If it’s still tacky I will wipe it down with alcohol. Thanks guys
 
What Stacy said should help and then give it a couple of days to completely set up. I would guess the same as above somehow the hardner did not work totally for some reason but should with a little time and warm temp.
 
Well that could explain why mine dried so nicely and quickly; I used it it in the summer when it can get pretty hot is my non-insulated shop/shed and left it out there over night. Seeing that I also live in WA in the Seattle area I'm glad this thread was posted as I may experience the same thing on a non-summer day up here in the rainy PNW.

Let us know if ya get it figured out, JT. :thumbsup:

~Paul
My Youtube Channel

... (It's been a few years since my last upload)
 
It is all dry now. It must have just been a tad slower then what was listed because of the lower temp of the man cave (spare bedroom). But it’s all good and the sheath is done.
 
I have used a lot of System 3 Clear Coat and it cures much better with 2:1 by weight ratio.

I now use Polymer Composites Max CLR it is glass clear, High Impact, marine grade and food safe resin. The price is better then System 3 and West System.

 
KCGGBC said:
Where do you get it from Adam?
Click to expand...
You can find it on Ebay and Amazon and their own web store

I suggest you give Polymer Composites a call (909) 673-1625 and ask for, Gerald Lapuz he is the chief chemist and CEO of Polymer Composites. Tell him I told you about it and he will know exactly what you will need.

They have many formulations of resins and he can recommend the best on for you. He is super nice guy and really helpful.
 
kuraki said:
AVigil AVigil compared to S3 clear coat viscosity, what is that resin like?
Click to expand...

Max CLR viscosity is similar to S3. He has several formulations for impregnating with different viscosity for the task.

For example here is a casting resin they have.

 
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