Xglass, Bamboo, Minimizing Fill coats and Glassing Data Points for Discussion

I have glassed two boards in the last week or so as an experiment.  Both 6-5 round tails pretty much the same shapes except one is my asymmetrical test board.  The non-asym uses bamboo for an exoskeleton with no stringer.  The asym is also stringerless and uses Xglass.   I wanted to try some 6 oz Xglass I got from Graphite Master on the non-bamboo.  I also got a small roll of 56 inch wide 2.3 oz glass plain weave from Thayercraft with the goal of draping it with the fibers aligned 45 degrees to simulate Xglass on the bamboo board.  My thought was that I could get similar Xglass effect with a lighter cloth and better protect the rails from dings.

 

I was also interested to see how much I could reduce the amount of fill coat needed to get a smooth finish when I used the 2.3 oz on the outside. I have found that by putting the finer weave lighter cloth on the outside of a lamination, you can reduce by 1/3 or more the amount of resin used for the fill coat. And in place of the resin, which adds no strength to the lamination, you add more fiber, which does add strength.  Mike Daniel is saying amen.

 

Well, pride goeth before the fall.  I thought I had it all  figured out.  But I had a few problems.  I thought it would be good to share a bit.  Actually, over all, it turned out well.  I am definitely liking where this is going, but I have a few kinks to work out.    See what you think.

 

1.     I am still convinced that a multi layer lam is the way to go.  Three layers of 4 oz is better that one layer of 12 oz or two layers of 6.  Just like G10.  Inter-laminar bonding, and better glass to resin ratio.

2.     Using smaller weave cloth on the outer lam to minimize fill coat and weight seems like a smart thing to do.  Exchange the worthless weight of resin with some fiber and reduce the amount of resin needed to fill the weave.  On the board with 2.3 oz on the outside, instead of using 7 oz of fill coat resin per side I used 3 oz.  I used the squeegee to move it around and cover the board, then the brush to smooth it out and get the needed finish.  I saved a half pound of weight (total both sides)  and didn’t have to sand the excess  off.

3.     Thought I could shoot two birds with 2.3 oz rotated 45 degrees.  The problem was that the light cloth moved around as I laminated and it was really hard to avoid bunching at the curves.  As I tried to pull it tight, it just bunched up locally.  It didn’t wrap the sharper curves on the round tail very well and left me with a lot of sanding on the wrapped laps.   I found on the curves that you needed lots of relief cuts to get it to wrap well.  This 2.3 oz plain weave was just hard to work with.

4.     Get some X cloth, too bad it only comes in 6 oz, makes for a heavy lam, but it handles really well.  On the asym I put it below a layer of 4 oz warp on one board and cut the 4 oz a littler longer at the lap  (see pic) but save your off cuts for underfoot patches AND fin footballs under the glass.  This stuff  rail wraps well.

5.     Use of 2.3 oz for X cloth, probably should be under the 4 oz. unless you are will to fight the cloth movement.  Perhaps there is a better style of light cloth.

6.     In spite of all the trouble I had during lamination with the 2.3 oz,  I really did save a lot of resin on the fill coat.  That 2.3 oz cloth almost didn’t need a fill coat.  (see Pic).  I would have normally used 7 oz of fill on a 4 oz cloth but instead used only 3 oz. 

7.     Weight diff:  I saved 8 oz of resin on the fill coat and used about 8 sq ft times two of 2.3 oz cloth, so the weight saved was 8 oz resin minus about 4 oz of cloth.  And the board ought to be stronger.  Ought to be.

8.      I used rail channels on both boards.  Using the 2.3 oz made this a big pain. I couldn’t run my finger in the slot to push it down and pull out resin without bunching and moving.   Using the 6 oz Xglass was no problem.  

9.     I will standardize on 4 oz. warp with Xglass.  For lighter weight glassing in the WMD mode, I will use the 2.3 under the 4 oz warp, until I figure out how to better use it and make it stay put on the outside of the lam.

10.  A lot of my findings are borderline anecdotal, but also have some solid experience and draw from proven lam’s and information I have gathered here and from the experts.  I can’t be bothered with writing them all down.  But I do welcome your thoughts and experiences.  If I have it wrong I hope you will speak up.

 

 

(The asymmetric:  one side about 1.5 inches wider, I used an 8 foot  gun template for the toe side and a 6 foot round tail template for the heel side.  the fins are offset fore and aft about 1 inch.  the single concave is semi asym.  I was afraid to get too weird.  I dunno.  could be a majic board, or a dog, if the former, I will give a full ride report. ha)

 

 

 

Here I am laminating the Xglass under the 4 oz warp.  Notice the 4 oz warp is longer than the X out of fear that it would unravel.  It didn't.  I wrapped both the top and bottom lams around the rails.  Sucker better not ding.

 

Here is the 4 oz/ Xglass lam before the fill coat.  I used 7 oz of fill resin on the deck.  Could have used 6 and been fine.

 

 

 

 

Here is the bamboo with 4 oz under and 2.3 oz over in the X position.  Slick, eh?  I really could have skipped the fill coat, but used 3 oz and could have gotten away with less using the squeegee to first move it around before brushing.

 

 

I used some X glass under foot for patches.

 

 

 

Here is the bottom of the bamboo.  I've gone minimal to make Oneula happy.  Next time I will just use some 6 inch wide arc's of bamboo on the deck and bottom rails.  And some underfoot patches.

 

 

I really want to make the 2.3 X glass work.  I know I can use it  successfully under the 4 oz in an X pattern, and I know that if I can get it to work on the deck I can save over half a  pound.  Probably more.  I think I need to build another couple of boards ad figure this out.

Just one more board.  Then I'll quit.  I know I have to quit.  Tomorrow.  Yeah.  Tomorrow. Just one or two more.

 

(I have probably offended everyone in AA.  Sorry.)

Greg, i use to play with same materials: balsa, veneer, Xglass warp and others.

Xglass+Warp combo is the winner. With my friends we put hard impact and stress on the test board with just little problem (poly glass peel off). I never see a stonger and steel flexible  board. Compsand is an old story for me strong but stiff. Veneer is cool for look.

Now i try others multiaxial stitched glass cloth form industry, with a bit of carbon in right place it’s seems to be better.

Sorry for my frenglish

Greg looks good, thanks for the update.

Sometimes that really light cloth works best inside the surfboard.

 

If you want a strong weight to epoxy cloth. I have had sucess with the Impact glass. It's 4oz but it sure has a bunch of fiber compared to warp or S. Kind of stiff, and kind murky.

I’ve never done any blind tests or anything (somebody here should!) but it seems to me that saving weight in this manner might be a trade-off for ding resistance. Keeping the heavier weave on the outside adds a touch more ding resistance due to the fact that it’s the “armor” (imagine HD foam on the outside of a veneer instead of under it), and by virtue of the fact that resin over cloth is not useless… it increases impact resistance.

But if you’re after light instead of bullet proof, sounds like a good way to go.

Big glass wave on the outside need more resin to be cover and sand without touch waves, so lamiante is thicker so it’s stiffer so it more pressure resistant.

As resin is less stiff than fiber (young module about 3 GPa for resin and 72 GPa for glass fiber) for same thickness a composite with more glass is stiffer, but as fiber is more dense than resin (2,6 kg/dm3 against 1,2 kg/dm3), it’s heavier.

With stitched fiber, no more wave, no more crimp, less resin, better strength in all aspect that’s the choice in HP composits application.

Sorry for my frenglish

Oops, NJ, I really disagree.  You are discribing a two phase matrix (foam and glass).  I am discribing just the strong component of the matrix, the shell.  If carbon fiber and E glass were laminated together, for the most part, it wouldn’t matter if the carbon or the E glass were on the outside.  As for the resin, pretty much its only role is to keep the fibers aligned and bond fibers together.  In the fill coat, if it weren’t for the need to smooth the surface hydrodynamically and cosmetically, we would apply it.    Anytime (for all time, no matter what?  making fun of myself here) you can replace resin with fiber, you are adding strength and toughness.

 

Lemat, you got it.

Resinhead, or anyone, how is impact glass diff from X glass?  I need to know this.  thx