lamination question

[55NSup]

One final question before laminating.

I have sealed my 1lb eps blank with latex based ultra lightweight spackel.
Will use a wet out table, no v-bag. Just hand layup from wetout table.

Should i brush/ squeege on straight epoxy on thé blank just before lamination?  sort of like a primer.

If I answer my own question : Blank seems quite porous. The spackle did fill the small voids, but there is a lot of unsealed eps exposed. So I want to prime the blank. 

Doing it tomorrow.

[55NSup]

[TallDude]

Yes. Use micro-balloon additive. Just mix your epoxy to the specified ratio, then mix in the micro-balloon powder to a yogurt like consistency. Brush and squeegee one side, then the other later. Real light hand sand after. One benefit is protecting the foam from hot spots on your first lay-up. If you  have a slightly deepened pocket of epoxy on your first lay-up, it can melt the foam away from your lamination. It happens a lot setting fin boxes, handles, and leash plugs. Any large voids where the epoxy can foam a larger mass, it will get real hot, and melting can occur. I seal my box cut-outs first and let cure, then set the insert later. Another benefit is, the evenly wet tabled cloth will bond to a uniform, non-absorbing surface. 

[TallDude]

BTW, I am by no means a professional glasser. I was taught to do this by some master glassers. Hobie does this on all there customs.

[Dwight (DW)]

Should i brush/ squeege on straight epoxy on thé blank just before lamination?  sort of like a primer.

I don't. Why slobber on that extra weight on the board. Just lam with your wetout table, without getting extreme on how dry you make it on the table. If vac bagging, there is no limit to how dry you can work the cloth. Wet fiber is all you need. Nothing excess between the weave is needed.


When NOT bagging, you want to wetout on the table with a little more resin. It will still come out light and it will stick to the blank better, since its not bagged. Your hot coats will be less tricky with more resin poured on the table too.

[55NSup]

DW,

Got it.
Do you use a fiber weight to resin weight calculation to determine how much epoxy to pour on wet out table? 

Or do you just go on feel and experience ?

As I recall I should have 50 g epoxy for every 100 g fiber.

[Dwight (DW)]

Or do you just go on feel and experience ?

Experience. By your second layer, you'll know.

[TallDude]

DW, I wouldn't just slobber any resin, or glue on anything either. Everything step is done with a balance of weight and insurance against leaks. I was going to just spackle my last board, as I had done the board before that. Just before I started I ran into Mark Johnson of Hobie who is a neighbor of mine. He said, and I quote: "For sure seal all EPS foam boards with micro-balloons because it greatly reduces pin hole water leak problems, and delam issues. We learned that along time ago the hard way."

[55NSup]

Tall Dude,

Thanks for the straight info. You guys helped me out earlier on which way to go On sealing the eps. I also did a lot research On swaylocks.  :
1. Seal with epoxy and microballons - better seal and adhesion - this makes total sense
2. Use ultralight latex spackel - easier to do- many claim it Works fine.

I decided to use the ULW spackle because it was easier and im sure this board will not be perfect and I will build another one next year. There has been a lot of New materials to find, and have never worked with.  I never intend to make this board for sale either.
Next year I will try the Epoxy + ballons. I have sealed a few areas around fin boxes with it and I can tell it not only seals eps better but creates a thin eggshell that I am sure improves strength.

Thanks for your help.

[Dwight (DW)]

"For sure seal all EPS foam boards with micro-balloons because it greatly reduces pin hole water leak problems, and delam issues. We learned that along time ago the hard way."

Makes perfect sense.

But being an engineer, I solved it my own way. I'm obsessed with light weight. I choose to ultra sonic leak test my boards to guarantee no pin holes.

Everyone else has to use more epoxy and cross their fingers.

[55NSup]

Wheew. Laminated bottom today and learned something.


We decided to wet out carbon first separately, put on thé board, then wet out glass on table.
It was a mistake. The glass got all distorted On table cause of epoxy left On table. Should have wet out both at same time. It went fast to wet out.
Or put dry glass directly on cf and wet out on board.

Carbon seemed really dry and should have brushed epoxy On rails before putting down cf. Did it after.

We managed to get it on, but it was pretty sweaty.

[Dwight (DW)]

video is private

[Dwight (DW)]

The glass got all distorted On table cause of epoxy left On table.

Prepare the table with your total bottom lamination "in layers"

1st layer - plastic sheet
2nd layer - glass cloth
3rd layer - plastic sheet
4th layer - glass cloth

pour resin and spread on table.
roll up cloth on pipe and transfer to board
tear layer of plastic sheet off table, exposing next layer of cloth (waiting and ready for resin application)

Table pre-setup is key for SUP work. Big boards. Saves time.
Staple the plastic to the table. Rip off and go to next layer.

[TallDude]

Ok DW, now I'm curious. Do you take the board out for a test run, then use the ultrasonic leak detector? I can't think of any way to test it, new in the shop.

[Dwight (DW)]

Ok DW, now I'm curious. Do you take the board out for a test run, then use the ultrasonic leak detector? I can't think of any way to test it, new in the shop.

Apply vacuum thru the vent bung. A pin hole will roar so loud it will blow your ears out in the ultra sonic headset.