Vacuume Technique

[hadley]

Is there a previous article that discribes the techniques in loading and firing off a vacuume press system. What are the finer details like setting up pleats etc...

Thanks in advance!!!

Hadley

[dante]

Pleats? …If you mean what I’m picturing that would be a bad idea. You do want a little bit of slack over your board/skis, so the vac film can really pinch down, but you don’t want any folds or wrinkles whatsoever over the vacuum sealant tape –they become little tunnels for air to creep in.

Here is how you can avoid them:


1. Stick down your vac tape in advance. Make a rectangle shape with the tape to surround your ski/board. Be sure not to cut the tape at each corner instead just rip the protective paper and bend the tape around the corners so it is one continuous piece of sealant tape. Where the two ends meet peel back the protective paper and overlap the tape –then replace the paper you peeled back.

2. IMPORTANT -Don’t remove the paper protecting the top of the tape until the end of your lay up

3. Cut your vacuum film so that it overhangs each outside edge of the tape by 5cm + (two-ish inches). Once you have a nice fit remove the vacuum film and set it aside

4. After you’ve laid up your ski/board (as described on this site) add a layer of peel ply (optional), then breather fabric and lastly the vacuum film you previously cut out including the nipple that seals the hose connection to the film (note at this point your sealant tape should still have the protective paper on it)

5. Now the important part to avoid wrinkles… Don’t peel off all the protective paper from the tape at once. Instead, while the vacuum film is hanging over the tape very patiently peel back the protective paper with one hand and use the index finger on your other hand to stick down the film smoothly without wrinkles. When you get to the end really work in the overlapping spot at the end of the tape. Don’t be tempted to hurry during this step. At this point you may feel under the gun because the clock is ticking on your epoxy but an extra 5 minutes here can save you from 3 hours of leak troubleshooting and a potentially ruined ride.

Hope this helps.

-Dante

[hadley]

We have made a long skateboard mold and it is standard practice to put pleats. Pieces of the sticky tape that run up from the base line to allow for deformation arround irregular shapes. I will try to put a picture on here. This layup resulted in a seal that we were able to come back to the nest day in tact.

I can't get this picture mechanism to work.[/list]

[dante]

I was picturing folds in the vacuum film not pieces of sealant tape. I’d like to see what you mean. Please post a picture if you can… maybe I can learn a new trick.

[dante]

Hey Hadley,

I did a search for pleats and vacuum bagging techniques. Mary results came up related to canoe building. It looks like the technique is to have points along your tape ring where you vertically place a piece of the tape to create a sealed fold to give a larger work piece (like a canoe) enough slack.

With skis or a snowboard your work piece stays pretty low to the mold. So although sealed pleats are a legit vacuum bagging technique I'd avoid using them for a snowboard/skis since it adds complexity and potential points of failure in the system...

-Dante

[King_of_the_Hill]

I'm an r7D composites engineer and make lots of vacuumbags for prototypes of airplaneparts, boats and now ski's. for a ski you don't realy need pleats BUT pleats do releaf stress in the bagging film! this important when using an autoclave (high pressure and heat) when just using it as an press, place the film as dante explaned. If you think it is to thight you can release the film with bubblegum removerspray (CO2) and try again