Vip and gloss on both sides, is it possible?

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#1

Ok so I have been doing VIP on glass for awhile. And now I want to know if anyone has ideas how to get a gloss finish on both sides of the laminate. I have seen a short video along time ago where someone used glass on the top, but I do not understand how I would allow my resin to flow across. I use enkafusion as my flowmedia.

So far the only idea I have is to infuse two separate sheets then vacuum bag them together. And doing that would waste alot of bag material that I would not need to use if I could just get both sides to come out gloss.

Anyways I am sure this is going to be another failed idea of mine, and you guys are going to say autoclaves are the only way. :frowning: But I thought it never hurts to ask.

Thanks,

#2

VARTM Lite is a closed mold system, using a little bit of pressure to inject the resin, and vacuum to pull it through. As long as you have long gel times and an understanding on flow patterns, you can have a 2 sided mold.
I have done tons of glass and carbon plates with a caul plate on top…no infusion media at all. You always have to make sure the edges are not open like channels, to allow the resin to just flow through. You can create a part, finish the top to a shine, and build a top half of the mold off that.
It helps to have a good fabric that flows well, but that all depends on your applications. Hell, I was doing a CF stitched fabric (ie: mostly unidirectional tows, no crimp, and no flow channels), with a foam core. Tool on top, tool on bottom. A 15x15" plate took 1.5hr to infuse.

#3

What do you use to create the pressure that assists the vacuum?

I have watched videos on VARTM and noticed it was always with fiberglass that was made for VARTM that had somewhat of a thickness to it, to allow the resin to flow threw. The fabric I have is 3k Carbon/Kevlar from BGF, so that is why I didn’t think it would work.

#4

every fabric has it’s own permiability, so you have to try it to see. I recently did a small 5" sq plate with a plate on top, and it worked fine. That was with 5,9oz woven, and a bit of uni (which is MUCH harder to infuse) carbon fabric.

Again, as long as you have a long gel time, it will work out. You can modify the geltime when you know how long the part takes to fully infuse later, so you can get the part out quicker.

The pressure is done with a paint pot. You add compressed air (with a regulator!!!) to the pot, the dip tube is on the bottom with the resin. Add air pressure, resin comes out tube.
Vacuum is to assist on the far side. It’s like RTM and VARTM mix.

#5

Riff - Thanks allot for your help. :slight_smile:

I remember their was a post just the other week about someone getting a pressure pot and was asking how to use it. I understand, and think I am going to try and get one. Do you have any good source’s for one? What would the price be, ballpark range is OK. And what type of psi are we looking at putting into this pot?

#6

I’m not really sure on VARTM Lite. What is the part you are trying to make? You might be able to get away with the 2part mold, and regular VARTM. I’m sure any pressure you add into the part via pressurized resin would have to be tested part-per-part basis.
pressure pots can be around 130$ from Mcmaster, might be cheaper elsewhere, like Harbor Freight.