Is a cat track essential if using a custom bladder

[gozaimaas]

Hey guys, this is my first thread, after reading just about every thread on the forum over the last few days. I am amazed at the knowledge base here so well done on that.
I ended up here after weeks of trying to find someone to make the board I have designed, hitting brick wall after brick wall and getting quotes that approached the price of a new small car!
I have decided to build myself a press and do it myself, the addiction has kicked in and my thirst for knowledge is raging.

So I plan on having a custom inflatable bladder made up which I think should negate the need for a cat track. Am I correct here or way off track?
I have designed a custom mould with perfectly shaped top and bottom pieces with a 50mm (2") gap. The bladder will travel past the ends of the board by some distance without changing angle so I dont think I will have a problem with lack of pressure at the end of the mould like I see some people were having due to the mould ending too close to the end of the job.
The way I see it I should have no need for a cat track, what do you guys and girls think?

Thankyou.
Leigh in Sydney.

[MontuckyMadman]

The cattrack is used to distribut pressure evenly across the ski not longitudinally.
you get a pressure imbalence in the laminate no matter what but it increases at the edges if the bladder overlapps. Look for doughboyshredders posts regarding this ther are diagrams and you will undertand. Too wide and you put extra pressure on the edge area and too small you dont get enough.
if the molds are perfect you could put the bladder under the mold and press that way.

[Richuk]

Your hose is going to be closer to the heat-blanket. I'm assuming you have this covered if you are getting it custom built.

Looking forward to photo's of this set up : )

[gozaimaas]

Thanks for the fast reply guys.
So it seems that a cat track is a must then, I dont want to bother trying to reinvent the wheel as such if it has already been proven to fail. In that case I can forget the custom bladder and just use 3 lengths of firehose like everyone else seems to do with success.
The mould has a perfect 50mm gap the entire way across which requires the hose to soak up the difference in the boards core thickness so pressing from the back of the mould will not work.
I am fabricating the press frame myself as I am a welder/steel fabricator and having the mould cnc routed.
I will go back and read the threads by doughboyshredder, and I will definately post a heap of pics when I get up and running

[twizzstyle]

Sounds like you're on the right track.

You can go without a cat track, I did for a while, and the skis that came out weren't terrible. But when I added the cat track, my results got way better (flatter bases). The idea is that you'll have purely normal (perpendicular) force on the laminate.

It's also more versatile than getting a custom one-off bladder made that will only work for one board. Trust me, this won't be the only board you make.

[gozaimaas]

My moulds will be cnc routed from 25mm mdf and placed side by side, there will be no gaps like I see most people have which require a lower cat track. This should negate the need for a lower cat track I think as the base will sit perfectly flat.

[twizzstyle]

Yeah, I think most people do just like what you're describing, no gaps, no lower cat track (myself included)

[gozaimaas]

Cool, thanks mate.
Ps I do turbocharging fab for a living if you ever need to know anything about getting your little rocket moving

[twizzstyle]

Ha! Awesome!!! I haven't touched that project in a few months now. Successfully made a lot of noise, and some huge fireballs... I suppose that was really my only goals with the project!

[EricW]

The guy that used to own November Snowboards in Minneapolis used one giant bladder that covered the width of the press and even popped out on the sides. The thing was huge. He didn't use a cat track and did full cap construction with it.