lex wrote:Cassette are extremely helpful when glueing your edges. Just glueing edges on using only clamps isn't going to be the most accurate. If you guys use crown bases, these bases are really sensitive & warp like a mofo as it has been noted. So basically you could be glueing your edges on to a warped base. The best thing possible is to have magnets in your cassette to hold the edges, then you don't glue them on, but thats $$$. Burton didn't glue them on in the N.American facilities(Vermont or Trak). Anyways, the most accurate & consistant way is to have a cassette...at least of the sidecut part. I've used steel edges & have done rivets spaced apart for the sidewalls alignment.
DBS, doing straight sections on a sidecut isn't easy, one you notice if it's not exact & being exact can be tough.
PSI, whatever you want to use, I can't do more than 50psi & that's to the firehose, which I use 2 of them. So the actual pressure is probably closer to 30psi to the board. So 80, might be 50 I guess. I personally rather keep the pressure to around 50, temp around 70c, keep the epoxy to under 40% of the fiberglass weight. This helps with a flatter base, less telegraphing & I don't need a lot of press to squeeze out the epoxy cause that's not the goal. In reality, I get 30psi, end up using too much epoxy & too high of heat since I have wired in my heatblankets correctly
I use 3 hoses at 80 so probably more like 90 at the board. Probably more than I need, but I know that I use more epoxy than necessary and I am using the pressure to squeeze out all the unnecesary epoxy. Bases come out perfectly flat. I do have a lot of telegraphing, but I think it looks cool.
Magnets would be awesome, but like you said, that's money. I have some ideas kicking around. I'll figure something out cheap and quick for a cassette. Kind of thinking about using a thin piece of plywood (taken from another richuk idea...) and cutting the reverse image of the board out of that and then laying it over the aluminum sheet. Not quite ready to try and get away from gluing the edges on, I just want a perfectly straight edge on my various straight sections. (I never really noticed till now, that none of my straight sections are perfectly straight), and I want perfection.
Im just finishing my cassete that I have built with magnets installed! I layed alum. over the wood mold and inlayed rare earth magnets then did a layer of 18 oz plain weave glass and resin over that to fill any inperfections in my magnets. then cut piece of alum. to exact outside dim. of my ski and glued/screwed it down! So Im hopeing to press first pair in this new cassette very soon so will let you know! and It was cheap to build! got magnets at princess auto and used old alum. trail signs from the hill (1.8mm thick perfect) and only burnt out 1 router (dont buy cheap routers) will post pics once I have some
DutchDesigns wrote:Im just finishing my cassete that I have built with magnets installed! I layed alum. over the wood mold and inlayed rare earth magnets then did a layer of 18 oz plain weave glass and resin over that to fill any inperfections in my magnets. then cut piece of alum. to exact outside dim. of my ski and glued/screwed it down! So Im hopeing to press first pair in this new cassette very soon so will let you know! and It was cheap to build! got magnets at princess auto and used old alum. trail signs from the hill (1.8mm thick perfect) and only burnt out 1 router (dont buy cheap routers) will post pics once I have some
Cool! Really looking forward to seeing your results. Sounds like a great idea.
DBS, I've been thinking about using a polypropylene sheet instead of ply. Cut the a full template out of the poly sheet. It doesn't bond to epoxy, so it would be re-usable, provided it turns out to be hard enough. Cut channels across the poly sheet to allow drainage and flex in the tip area. Insert into aluminium frame.
Eg.
___________________________
__l l_______l l______l l____
Not had to use magnets so far - 4Frnt had a good set up though.
Sheet of 16ga steel... secure your best work of base with edge on it... take more edge teeth facing OUT opposite the edge thats on the board... tack weld this edge down to your steel sheet. youll want room for expansion SOMEWHERE probably or u get lumps and waves... no??
Brazen wrote:That works, good idea Doug We use stepped aluminum, steels probably WAY better for the long haul and "channels" for the squeeze out, so far so good.
Someone forget to put water in your bowl? I mean really, if you ever actually had something useful to say or anything to actually contribute it would be different...show us YOUR cassettes there, barky. Or did I miss the part where you actually did anything but critique everyone else's efforts? Plus, there's that whole "no cassette" repeatability issue, at the start of this thread, and I'm sure that DBS' pressure, as I said, is the problem. Sue me. Tell you what, I'm just going to stop saying anything...you've cured me, MM.
The value of a cassette is not the aesthetic value of the result, which can be created without a cassette (per an early post from Brazen), but the seal it forces between the edge and the base - it adds pressure where there wasn't any before. This is in addition to solving the lateral movement of the core. The drawbacks have been previously stated.
edge ------> [ ][ <---- base
Having said that, its not necessary, its just a choice, but the great thing about this thread, is new cheap and easy ways to create a cassette. More please
Someone forget to put water in your bowl? I mean really, if you ever actually had something useful to say or anything to actually contribute it would be different...show us YOUR cassettes there, barky. Or did I miss the part where you actually did anything but critique everyone else's efforts? Plus, there's that whole "no cassette" repeatability issue, at the start of this thread, and I'm sure that DBS' pressure, as I said, is the problem. Sue me. Tell you what, I'm just going to stop saying anything...you've cured me, MM.
HA! Gotcha)[/quote]
MM has contributed more to this forum than most, especially you (although I do appreciate that you finally made an attempt in this thread).
That being said, the problem I was describing is caused by a combination of factors. Heat, pressure, and lack of a cassette. It is possible that I could solve the issue by using less pressure, but that can create other issues. Pressure is a good thing. There's a reason that none of my boards have had any delam issues. Heat is pretty much a must, imo. Non heat cure resins are just not as strong, and without heat you get a more inconsistent wet out of your fabrics. A cassette is necessary for high pressure heated applications. And as richuk stated it creates a better edge fit.
the screws are just to show where the magnets are! [/list]
I have a bit of space around it and am going to use small wood wedges to help force the edge to the base!
Now Brazen you metioned "channels"? what for??
As far a warping etc. I eliminated that by not using heat and using System 3 silvertip laminating epoxy! Just takes a long time in the press (5hrs) and put in heat box to finish cure
So this might be B.S but Ive heard that epoxy cured at room temp. 75 F will cure to a better bond as long as its left to fully cure, like a week!
doughboyshredder-Not too sure you want to part with your heat so this may not be an option
Channels allow the epoxy to drain away from the base. Or you could cut your fibre to size, which reduces the amount of epoxy within the mold. Be careful how you move the fibre once cut, as it will fray. Fibre will expand by about 1 mm when wet, so its not the biggest issue.
Just match sticks! cut off bussiness end and super glue to cassette on outside of side wall. ive done this before I had this cassette to hold base/edges then higher pieces for the core and they become part of the lay-up and just cut off during trimming
We use stepped aluminum, steels probably WAY better for the long haul and "channels" for the squeeze out, so far so good.
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