Hi im doing a project for 8th grade and i decided to build skis. Does anyone know where i could buy or order the materials for the skis and the epoxy? Also i decided to use a clamp press but i don't know how to build one. Can anybody give me directions on how to make one?
Thank You
Building a clamp press
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Jgolden7704
- Posts: 3
- Joined: Tue Nov 21, 2006 7:51 am
- Location: Philadelphia
Re: Building a clamp press
here you can see a way of building a clampingpress: http://www.stud.uni-karlsruhe.de/~uryo/ ... resse.html
this guy used some threaded rods - maybe the easiest and cheapest way of building a clamping press
this guy used some threaded rods - maybe the easiest and cheapest way of building a clamping press
plywood freeride industries - go ply, ride wood!
unless you have that much threaded rod lying around, i would be surprised if building this setup is actually cheaper than just vacuum bagging. not only will you have to purchase that many rods, but also you have to build a top mold that fits extremely well. with the vacuum setup your biggest purchase is the vacuum pump (a hand hand one can be bought at an auto store for under 10 bucks). the bagging material is all available from any material supplier (fiberglasssupply.com is great). with the vacuum setup you also only need a bottom mold and it doesnt need to be nearly as accurate as in a matched mold setup (ie. clamp press or bladder press). most of all, the pressure from the bag will be higher and much more even. i think you will be more pleased with the results.
Well, first of all, you do not put to much resin, then the excess resin is just squized out of the ski and stay between the ski and the bag. It can even be sucked through the connection and the tube: it happened to me once.mp_skier wrote:where does the excess resin go when you are vacuum pressing though
if done right, the resin should never go into the hose. we dont even use a resin trap in our line because this has never been a problem. over the layup you use a release film or a perforated release film (depending on how much resin you want to draw. we just use a layer of nylon film. over the release ply you have a layer of breather...this is an airy cloth (like fleece or felt). the breather is a NECESSITY...it allows the vacuum to pull over the entire part and not seal itself off under the vacuum line port. excess resin is drawn into this breather layer. this layer absorbs your excess resin, so put an extra swatch of breather under your port.
both the release and breather can be bought from suppliers for dirt cheap (they are disposable layers) or you can use common household stuff (painters dropcloth and fleece). for bagging i recommend the 36" tube bagging from fiberglasssupply.com, your whole mold can fit inside so all you have to seal off are the ends. if you have bag clips for the ends, the whole process can be quite fast. feel free to ask any questions you have on the process, as you can tell i am quite a fan of it.
both the release and breather can be bought from suppliers for dirt cheap (they are disposable layers) or you can use common household stuff (painters dropcloth and fleece). for bagging i recommend the 36" tube bagging from fiberglasssupply.com, your whole mold can fit inside so all you have to seal off are the ends. if you have bag clips for the ends, the whole process can be quite fast. feel free to ask any questions you have on the process, as you can tell i am quite a fan of it.
What do you guys use as a through bag connector?
Any reason for not using thick cardboard as a breather fabric?
I am trying to get my getto vaccum bag system to work
Thick polythene sheet folded to make an envelope, sealed with duck tape. Fridge compressor to draw vacuum, but using a household vacuum cleaner to initialy draw out the air (fridge compressor is very low volume).
At the moment I have a water resistant electrical fitting (the sort of thing you would use to seal where a power cord goes into an extarnal box) as a through bag connector. Washers and bike inner tube to seal one end and the internal rubber seal is tight on silicone tube on the other. Being plastic I can only tighten it down so hard before I risk cracking it
Any reason for not using thick cardboard as a breather fabric?
I am trying to get my getto vaccum bag system to work
Thick polythene sheet folded to make an envelope, sealed with duck tape. Fridge compressor to draw vacuum, but using a household vacuum cleaner to initialy draw out the air (fridge compressor is very low volume).
At the moment I have a water resistant electrical fitting (the sort of thing you would use to seal where a power cord goes into an extarnal box) as a through bag connector. Washers and bike inner tube to seal one end and the internal rubber seal is tight on silicone tube on the other. Being plastic I can only tighten it down so hard before I risk cracking it
The best through bag connector is a tire valve for a mag wheel which are about 5.00 at a Napa auto parts store. They are a threaded fitting which get sealed by silicon and big washers on either surface of the bag. With a tiny set of pliers extract the valve so the vaccum will draw through the valve.Idris wrote:What do you guys use as a through bag connector?
Cardboard strips work fine for bleeder fabric.I also use some high density foam which does not crush under the vacuum.
I've not been able to get a good seal with duct tape on the heavy vinyl I use but mastic or vinyl glue work fine.
Tony
I've used epoxy, mastik tape, release fabric, breather fabric, and suction cups from jamestowndistributors.com. The breather fabric absorbs the excess epoxy. The suction cups are easy and work well. I just cut an "X" into the bag, place a few layers of extra breather fabric under the "X" and press the suction cup down until the vacuum builds up enough.
Good luck!
Good luck!