Composite Test Samples

[Jim Dodd]

I'm going to hold off with glassing Black Pearl awhile, as we have some colder weather and snow coming in. I don't want any distractions !

But I did go down to the shop to wet out a few test samples !
Three things concerned me ? One, how clear the S-glass from Sweets would be? Two, I plan to glass the Starboard side, first, and let it set, before wetting out the Port side. I hope this test will help me see the effect ! Three? I wanted to wet out a patch of Kevlar and Carbon, and see how stiff they will be together.

Sweets S-glass, actually wet out clearer than the S-glass I used on Vader ! That's Great !

I can plainly see where the wet line is on the Kevlar ! That is good ! I'll check it tomorrow, and see how the other side wets out, and see if it will be a problem.

Carbon Fiber, is difficult to see where the wet line is, so when I get to that point, I'll have to be methodical, and thorough !

A couple of pics.

 

[alsg]

I used S-glass from Sweet composites on my build. I can faintly see the weave up close.

 

[Jim Dodd]

I used S-glass from Sweet composites on my build. I can faintly see the weave up close.

Thanks !

I expect to see it faintly ! The S-glass I used last time around, and I have enough scrap to do a side by side comparison. Sweet's is definitely clearer ! They both are tightly woven, and I feared they would be hard to wet out. They weren't.
If I'm not too busy moving snow, I'll pull the samples off the plastic, and get a better visual on them.

I'm all ready thinking on my next build, and may fore go the Carbon, and either use a thicker Kevlar, or two layers.

Jim

 

[BWCA66]

Jim, what are you using for your resin?

 

[Sven]

Interesting concept Jim, I'm excited to see how this works out for you. Hopefully all goes as planned!

 

[Jim Dodd]

Hi Gene
RAKA 127 resin, and 350 Non-blushing slow hardener.

I have some of Their UV- inhibited resin, that I hope to use on the last fill coats, and inside.

Jim

 

[Jim Dodd]

Interesting concept Jim, I'm excited to see how this works out for you. Hopefully all goes as planned!

Keeping my fingers crossed ! Thanks !

Jim

 

[BWCA66]

"I can plainly see where the wet line is on the Kevlar ! That is good ! I'll check it tomorrow, and see how the other side wets out, and see if it will be a problem.

Carbon Fiber, is difficult to see where the wet line is, so when I get to that point, I'll have to be methodical, and thorough !"

Jim - while that is true I have found all in all though that the carbon is easier wet out as it soaks in the resin whereas the kevlar doesn't and you need to make sure that you have a good coat on both sides - not as forgiving as glass or carbon. That's why when you scrape a hull that has kevlar in it you see the strands of fiber where you don't see glass or carbon strands.

 

[Jim Dodd]

"I can plainly see where the wet line is on the Kevlar ! That is good ! I'll check it tomorrow, and see how the other side wets out, and see if it will be a problem.

Carbon Fiber, is difficult to see where the wet line is, so when I get to that point, I'll have to be methodical, and thorough !"

Jim - while that is true I have found all in all though that the carbon is easier wet out as it soaks in the resin whereas the kevlar doesn't and you need to make sure that you have a good coat on both sides - not as forgiving as glass or carbon. That's why when you scrape a hull that has kevlar in it you see the strands of fiber where you don't see glass or carbon strands.

I've distorted enough cloth with a squeegee and brush, that I turned to foam rollers long ago ! I could always see the vertical lines in the cloth from the squeegee, and a brush seemed slow.
Started with 1/4" nap, Black roller covers. They were an improvement. But now those little Cigar foam rollers have my Heart !. From years of Packing Plant, repetitive work, My wrists don't manipulate a squeegee very well anymore.

I will look the Kevlar test piece over closely ! Trying to avoid air holes ! Thanks for the Heads Up !

Jim

 

[Jim Dodd]

Checking my records. On the S- glass test pieces, The S-glass, I used last year, was 9 oz. The S-glass I purchased from Sweets, is 6 oz. That explains the clarity issue between the two !

Just a heads up !

Jim

 

[BWCA66]

Jim, are you using any type of roller to work out any bubbles?

 

[Jim Dodd]

Not yet ! I didn't really have any bubbles, in the previous composite builds. A few pinholes, very small, but I think that the peel ply might have been responsible. No Peel Ply this time ! I do have a blower (Hair) drier handy. Before I understood the principle of outgassing, and how to control it with falling temps. I used a Hair drier a lot !

Do you think I will have bubble problems ?

Jim

 

[BWCA66]

Jim,

Not really bubbles but using a hard roller you can make sure on kevlar that the resin gets between all of the weave which is what you want and is tight against the next layer. You can almost hear and feel it "pop" as you roll it. This is what we use.

 

[Jim Dodd]

I made up one of these, from a foam roller that was saturated with res and cured. I'll see if I can locate it !
I think I understand the need for that bubble busting roller .

When I looked at the back side of my samples today, I can see areas of excess resin, and some starved. The heavy plastic I wetted the samples on, was wrinkled, and the resin pooled in some spots, and really showed the wrinkles in the plastic. This plastic was a lot thicker than the Window film I used on the hull !
I remember, on Vader, having to scrape some areas, where the resin pooled, and then left some areas starved.


Like this.

Thanks !!

Jim

 

[BWCA66]

Do you suppose the heat of the resin reacted with your thicker plastic more than thinner window film that might be formulated to tighten when heated?

 

[Jim Dodd]

The heavy plastic is just more stubborn, than the film !
As I reflect more on Vader, it was on the vertical sides, that this problem occurred. Another reason to vacuum bag ! !
Hoping that by tilting the strongback, and applying epoxy to one side, this will help ! Fingers crossed !

Thanks for your imput, as I know you have Way more experience in this sort of thing !

This cold spell may be a blessing, giving me more time to ponder this build !

Jim