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Finished pneumatic press

Posted: Sun Oct 22, 2006 11:36 pm
by Head Monkey
I finally finished the bulk of my snowboard press and pressed the first board with the new system. Pics and a little bit of description here: http://www.happymonkeysnowboards.com/Mo ... nstruction The board came out perfectly! I'm very happy with the pneumatic press. The results are far superior to what I was able to achieve with the vacuum system I've used for the past 4 years.

I have some plans to change the track suspension system to something a little less hokey, a more convenient air control manifold, and actually mounting the control box to the press. I'm using a 60gal compressor which allows me to bring the bladders up to 60psi without the compressor kicking in. The heat blankets came from MEI and work beautifully.

I got many good hints and tips from this forum. Thanks to you all.

Image

Posted: Mon Oct 23, 2006 9:12 am
by BigG
Congrats to you and your very nice press.

Can you tell us what the biggest differences are in your results with the vacuum bagging and the press?

Bigg

Posted: Mon Oct 23, 2006 9:37 am
by G-man
Very, very nice all the way. The alignment and finish work on the board are flawless.

G-man

Posted: Mon Oct 23, 2006 10:49 am
by mattman
So you were able to seal the bladder without any sealant? (the ends, not the ports). I have a similar assembly for the ports, but havent had alot of luck sealing the ends...i was using c-channel and silicone caulking. if you just clamp the hose closed without any filler-goop, dont you get leaks in the pinched ends? I also had a problem with the bolted channel creeping down the hose...this eventually elongated the holes that the bolts went through and ended explosively. I have more hose to try again, but want to make sure i understand how you did yours so simply first!!! By the way, VERY professional construction you have...you are living my dream job!

Posted: Tue Oct 24, 2006 8:23 am
by justin56
Head Monkey,

Wow! Good job!

Posted: Tue Oct 24, 2006 8:40 pm
by Head Monkey
Thanks for the compliments. I enjoyed building the press.

Here are the benefits I see of the pneumatic press over vacuum bagging:

1. The top sheet is significantly smoother. Use a glare to see just how smooth (or not) your top sheet is to really get a handle on this. With vacuum molding the top was never smooth. It always had subtle variations in it.
2. The laminate is thinner with less resin trapped within. This is especially obvious on the top side: I can see the thickness of the top layer of glass where I drill out the inserts. The upper layer is less than half the original thickness. The extra pressure squeezes out more resin, and combined with #3 below yielded a board almost 150g lighter.
3. Better ability to heat the laminate: I use heat blankets on the top and bottom. The press allows great contact between the top heater and the board. Better heat = better resin flow before it gels = less trapped resin.
4. Adjustable mold: it is a lot easier to make a nice adjustable mold system without having to worry about the mold surface being airtight :)
5. Far less waste: I used to buy breather fabric and bag material in bulk rolls, and vacuum sealant tape 10 rolls at a time. Extra cleaning on the mold surface to ensure a good seal with the vacuum tape. Complicated extra layout of breather fabric along the edges of the base to ensure greater resin wicking from below the top sheet. Ugh… I won’t miss any of that :)

Much of this stems from two simple facts: with a press the top of the board is pressed evenly with a nice smooth piece of metal, and it’s pressed at much greater pressure. I used nice Gast vacuum pumps and could regularly draw 24.5in/Hg. One atmosphere at sea level is 29.92in/Hg for 14.7psi on the part. 24.5in/Hg gets you 12.04psi. What do you get with a pneumatic press using two hoses at 60psi? Well, it depends on the board surface area, the contact patch of the hose to the bars, etc, but you’re looking at something from 30-40psi no problem.

On sealing the hose ends: that’s right, I used no extra sealant on the hose ends. Just angle iron, grade 8 bolts (3/8”), and a reasonable amount of torque. Given the type of hose I have (just old fire hose, not sure of the specific kind) this works just fine. Good tip on watching for the bolt holes to elongate… I’ll keep and eye on that.

Posted: Tue Oct 24, 2006 9:25 pm
by G-man
Hey Mike,

I just took another look at your photos. Your clean and simplistic graphics (as compared to most of the bizarre contemporary graphics now-a-days) are so pleasing to the eye. Your graphics look like they are sublimated. Do you do them yourself?

Also, you mention that you are heating from both top and bottom. I am revamping my press to do the same. I'm not quite sure how to insulate the bladder from the top heater. I don't use a cat track. I'm sure that using one helps to dissapate the heat before it reaches the bladder. My fire hose is only rated to 122 F. I wouldn't want to be too close when/if it got too hot and blew. The answer will probably come to in my sleep, like everything else does.

G-man

Posted: Tue Oct 24, 2006 10:19 pm
by iggyskier
Press looks awesome!

My question is similar to what G-man asked - how did you incorporate the heating blanket into the top mold?

what types of cassettes are you using?

thanks! :D

Posted: Wed Oct 25, 2006 10:04 pm
by Head Monkey
Yes, the graphics are sublimated. I don’t do it myself. I use a company called Creative Edge Graphics that’s here in WA. I don’t think they have a web site… I can dig up some contact info if anyone is interested.

I rely on my cat track to insulate the bladders from the top heater. It seems to be working pretty well, too. The track bars make a pretty good heat sink, especially if you blow air through them :)

I don’t use specific cassettes, just sheet metal. From top to bottom I have (or will have) the following: top mold spacers, hoses, track bars, metal sheet, heater, metal sheet, metal sheet, laminate, metal sheet, metal sheet, heater, metal sheet, base mold. Basically 3 sandwiches: two heaters and one laminate. The heater sandwiches stay in permanently, and the laminate sandwich is built up and slid in between the other two.

Posted: Wed Oct 25, 2006 10:18 pm
by G-man
Mike,

Thanks again for the detailed info. I might take you up on the sublimation referral at some point in the future. Right now, I have to focus on getting the skis to stay together before I start thinking to much about making them pretty. I just really like the looks of your boards.

Your heating system set-up is very practical and functional. I'm trying to avoid the cat track (since I'm just pressing one ski at a time), but, as you describe, it's such a logical way to disipate the heat of an upper heater.

G-man

Posted: Wed Oct 25, 2006 11:26 pm
by iggyskier
Head Monkey wrote:Yes, the graphics are sublimated. I don’t do it myself. I use a company called Creative Edge Graphics that’s here in WA. I don’t think they have a web site… I can dig up some contact info if anyone is interested.
I would be very interested in contacting these guys to see if I could get some quotes on topsheets from them. Thanks!

One more question - could you describe the adjustable mold a bit more? I believe I understand how the tip/tail sections slide, but I am unsure of what the center camber of the mold is like. You said you modeled it after a guy on Graf's adjustable mold.....in his when he moves the tip/tail blocks he had to put in a new 3/4" section of MDF that was screwed into the mold.

here is a photo:
Image

Image

Did you do this as well?

Posted: Thu Oct 26, 2006 11:01 pm
by Head Monkey
Craig Schneider, Creative Edge Graphics, 2003 B St. NW, Auburn, WA 98001 (253) 735-5111. Good guys who’ve been making top sheets for skis, boards, wakeboards, you name it for years.

Yup, I pretty much did what the pictures you posted show: an extra piece of 3/4" MDF to cover the camber section and provide a smooth transition from the nose/tail sections. I don’t screw it down, though… I use it to line up the nose/tail sections, then I lock those into place and just leave the center MDF section sitting there… the press pushes it down just fine. Sure, you need a different length of MDF for each effective edge length you do, but realistically you’ll end up doing a limited set of different EE’s, so you’ll end up with a small stack of MDF sections of different lengths.

Posted: Sun Oct 29, 2006 7:39 pm
by hydrant71
thanks for the contact mike. like i said before, all your stuff looks great.
your press, boards, website, everything looks sweet. your customers are
going to dig your boards even more with the introduction of your new press.

Jason

bolts

Posted: Wed Jan 24, 2007 5:26 pm
by sam
Mike.
I noticed you bolted your press together and am planning on doing the same. My first question is how did you put the holes into the beams for the bolts to go through? Can a drill press do this? Also, for anyone who can answer, it looks like this press was held together using 32 1/2" grade eight bolts, I am thinking about bolting mine together using twenty 3/4" grade 5 bolts. Will this be sufficient. One other thing to consider is that it is a single ski press, so there will be much less pressure. Thanks for the help.

Posted: Tue Jan 18, 2011 10:35 pm
by BCCB
I have been doing some research in anticipation of building my first press. So far seems like I-beams are the only way to go. I was hoping to try something lighter weight that can be broken down into sections and moved if need be.


What size I-beam am I looking for? What is lightest weight I can expect if I go this route?

Anyone know of places that source this kind of structural steel?


BCCB