Friday, May 24, 2013

Freakin' Brrrrrrrrrr!

Ok Mother Nature. That's 'nuff foolin' around! Warm it up a lil' bit would you please?

I guess I wasn't kidding about the monsoon season having arrived. Cold too. Only 5 Deg C in the shed this morning. A degree or two colder and we could have expected snow! Yikes!

Anywho, too cold and damp for my ole' bones in the shed so I made a run to Canadian Tire for an el Cheapo grinder. I bought one of those flappy grinding discs at Lowes and was going to give it a try today except for two things:
  1. My grinder is a POS
  2. I can't find my grinder!
$30 later and a Timmies I have a new grinder. We'll give that a spin tomorrow. The rest of the afternoon I tinkered with an idea that's been rolling around in my head for awhile. It has to deal with fixing the bubbles in the laminate. You likely won't remember but way back when before the boat project I tinkered with resin infusion and have a full vacuum pump and setup in the basement.

Somewhere along the line I bought from eBay a Gast venturi vacuum generator. I think the original idea was to use it for infusing parts but the Robinair was cheap and likely more reliable. The Gast sat on the shelf gathering dust till today.

The vacuum generator is on the left. It uses air from the compressor to generate the vacuum. In the middle is a vacuum guage and the black thing on the right is an inline filter that I use as a resin trap. You don't want uncured epoxy getting into the vacuum generator.

"So what's it all for?" you ask. Well awhile back when I was fiberglassing the bottom of the boat I ran into a problem with some bubbles forming under the laminate. This isn't good and they can cause big problems down the road so they have to be fixed. I'm drawing on my experience with resin infusion and will use a vacuum to pull epoxy through the voids and fill them up completely. I'll use this slightly more portable setup in the boat shed. It's really a simple process actually. 

Here's a panel being infused.

The black loopy thing near the bottom is a split wire loom used to keep wires organized. In this application it's being used to deliver epoxy to the laminate which is compressed under a plastic film against a melamine table top. A plastic mesh and plastic film cover the laminate to allow the epoxy to easier flow into the material. At the top of the picture is the vacuum inlet. You can see the epoxy being pulled through the laminate towards the vacuum. When the part is about 3/4 done I stop the epoxy and the vacuum pulls it all the way through.

And these are the materials that get gashed when the process is complete! I'm not totally comfortable throwing it all out but it's pretty much useless now.

This is the finished part.

With any luck I'll be able to quickly and completely fill all the bubbles. I think just for my own peace of mind I need to do it right.