Problem with Entropy SS CPM

[skidesmond]

I've since done some upgrades and tweaks to try and get this to lay up a bit better. A lot of effort has gone into even pressure and good contact in the tips.

When the cassette gets pressed my temp goes down to 65c and is back up to 82 inside of a minute or 2.

I've pressed anywhere from 30 to 80 psi

tried jelled epoxy from the previous layup thinning it might not run, it did

doused the ends in extra goo

sanded, rubbed mek and rubbing acl, flamed

added the second bladder for better tip pressure and tried pressure variations between the 2

added shiims over and under the cassette to fill in any possible gaps.

The one thing that DID work is using huntsman resin. When I pull it, the laminate is perfect. Here the current setup.

I am pretty stoked on the second bladder. It opens up the cavity a lot more and it helps the track fit into tight corners

https://docs.google.com/file/d/0B0MF1yy ... sp=sharing

https://docs.google.com/file/d/0B0MF1yy ... sp=sharing

Need permission to look at docs.

[prospectsnow]

Sorry about that.
I would have just posted on here but the Image tag was working correctly.
Anyway, you guys should be able to see now.

[MontuckyMadman]

I have to tell you I have pressed over a dozen skis with a similar radius bend, pretty sharp, and never had a prob with the same epoxy.
You sure your ratios are right?
.4/1?
I really think something is going wrong and its not the epoxy.
Cook it longer?

[Brazen]

If it's delamming there's too much pressure at the tips, you're over compressing at the point the delam happens. Are you putting a base thickness spacer on the tip and tail outside the layup to prevent that area from over compressing?

[holmtech]

I've had some delams at the tips/tails using entropy, but pretty much chocked it up to: too much pressure at the tips/tails, and not enough heat at the ends.

The heat issue was due to the skis being longer than my heat blanket. Easily remedied.

The pressure issue was as a result of my "bladder space" being thick enough that the bladder was trying to straiten out at the ends. I've fixed this but I'm liking the 2nd bladder setup. I might build a similar setup, but put the extra bladder above the top mold so the base mold is supported by the press frame. My firehose is this double layer fabric stuff and is super stiff when pressurized. The red stuff looks like it would handle curves slightly better.

Brazen, I like the spacer outside of the tip/tails idea. My next layup will have that.

+2

[prospectsnow]

Good info guys.
I'm agreeing with the pressure issues and going to try a few more ideas.
Brazen good call on the tip spacers. Thinking I'm going to cut out some extra base material for this.

Still weird that huntsman holds on.
I'd rather have entropy work because huntsman 557/994 smells like cat piss.
557/5049 formula isn't so bad, but it is only offered in 55 gals from krayden.

It is time to get rid of the cat track completely.
Fun

[JSquare]

More of a question for the gurus in this thread....

From what I've read elsewhere in the forum, the gap between the top mold and bottom mold is pretty important. Too much of a gap let's the hose expand and do some funky things with pressure. I'm looking at your picture at the front of this thread and my gut tells me that the top mold comes up a bit short and the hose is expanding and taking some weird shapes on the end.

This make any sense or am I all wet?

[prospectsnow]

You are on the right track JSquare.

Especially in the tip and tail the hose is trying to straighten out. This project is tough because the tips have a tight radius. To fit a cat track, hose, cassette, and layup i there ends up being a lot.

When a radius gets tight the cat especially likes to bind up. It might even look like it is making solid contact but in reality it is barely pushing. You'll see that when you get wrinkles in the topsheet.

If you have a tight radius or are having trouble getting contact you can go with smaller cat tubing, space the track out with washers in the tip area, or maybe even ditch the track completely.

Ditching the track completely is where I landed.
Brazen, the base thickness spacer was a good idea and i think that helped because I think I was bottoming out too..
I haven't tried Entropy again.
I've been using huntsman 557/994 which works but smells like bleached a**hole.

[Brazen]

Glad that worked out for you! Yea, on tight radius bends for SURE you're better off with matching top and bottom forms...they have their own ish but when you get the parts dialed in you are good evertym