Does number of glass layers matter?

If I’m using regular e-glass, does it make a difference if I use 3x 4 oz layers or 2x 6 oz layers? Or is 12 oz  of glass just 12 oz of glass no matter how many layers it takes to build it up?

 

Thanks.

 

Jesse

It does make a difference.  Years ago I posted some info from Graphite Master on this and the term they used for the added strength.  I am unable to find it.  I probably made it up.  ha.  But, it’s one of the reasons G10 is so strong.

Maybe the materials engineers will chime in, but 3 by 4 is stronger than 2 by 6.

Which one uses more resin? 3 by 4 or 2 by 6?

crunch

Adding to the question, if that’s OK, Fresh

I know the common way is to lam the multiple layers at the same time, but my reading of the literature indicates that this diminishes the effect of added layers, and the layers should be lammed separately for best strength (separation between the cloth layers adds strength, I think)

Anyone able to confirm/ reject?

3 by 4 will use less resin to fill coat.

I strongly believe that the only reason for laminating several layers at the same time is to cut on production time. If done properly, there is no way you’re gonna add any weight by laminating separately different layers; And of course, the more layers the tougher it is for a given weight. But laminating three 4oz layers one after the other would take 3 times what it takes to laminate two 6oz layers together.

Ooops; Double post. Sorry guys.

[quote="$1"]

If I'm using regular e-glass, does it make a difference if I use 3x 4 oz layers or 2x 6 oz layers? Or is 12 oz  of glass just 12 oz of glass no matter how many layers it takes to build it up?

 

Thanks.

 

Jesse

 

[/quote]

I agree with Greg ,Dean and Balsa. But there's more going on....It sounds so simple at first.  Your foam makes a big difference. The weight of the rider matters too. How you over lap matters too..... And..... 4 oz is easy to blend / freelap...

My mentors taught me that 3 layers of 4 oz would be stronger than 2 layers of 6oz.....but not a whole lot stronger....

...And...

......a good 6x4 deck with a 6 bottom will get you a very strong surfboard.....

How you over lap the rails changes things too....

Welcome to Swaylock's.....

 

Ray

The ‘crimp’ is less severe on a thinner, flatter weave (or non-weave) than a thick weave. So 3x4oz is ‘stronger’ than 2x6oz, twill is stronger than the typical surfboard plain weave with twisted strand, etc.

http://www.vectorply.com/reinforcemt/about.htm

http://surfxglass.com/why_xglass.php

On the other hand, a laminate made up of more layers may end up thinner(and lighter) which may make for a more flexible laminate which may make it easier to dent and buckle(but harder to break/shatter?). Ideally you would use this weightloss to add more fiber to the same weight. If this effect is substansial in a hand layup I don’t know.

regards,

Håvard

The standard lamination for a 5/8" to 3/4" thick “wakeboard style” core-cell foam cored kiteboard was  : 3 x 6 oz. deck with heel patches ,   and  a   3x 6 oz bottom…

That was  a lot of glass to lay down “dry” and wet out all in one go… I didn’t like 6 oz. because it lapped  poorly around the extremely thin rails at the tips of the boards, and showed too much weave, so I switched to 4 x 4 oz., and then to 3 x 4 oz.S with patches under the feet…

The multiple layers of thinner cloth lapped far better, and left far fewer pinholes after vac bagging…

I got to the point where I’d wet out  2  dry layers of  4 oz using an equal amount of “weighed” epoxy…

Then I’d carefully roll on the last dry layer of 4 oz S and squeegee it down firmly to the previous 2 layers of cloth… This third layer acted like a permanent “peel ply” and drank up the excess resin out of the first 2 layers perfectly…

If I needed to add a few more grams of resin to the completed laminate to remove any “dryness”, I could if needed… I didn’t worry about any recommended  vacuum bagged glass to resin ratios, other than a healthy  50/50 balance on the first 2 layers of 4 oz cloth and goo…Adding the third layer of 4 oz, looked after the proper fiber to resin ratio in the end…

I’ve applied this to kite-surfboards, and now favor multiple layers of 3.2 oz /3.6oz as well as 2.3oz cloths… Love those 2.3’s  for the last " soak up"  layer,although they can “float” on the resin… All the more incentive to use that “out dated” vacuum bag tech…lol

The boards need less sanding/hot coat material, because the outer glass is pressed so " fine"  …

Just my $. 02… That and 3 bucks will get you a Starbucks coffee…;))

 

So lets say for instance.

If I just put down 6oz on the bottom (cut lap on top), then say did a 4oz over the top, let it dry out and cleaned it up on the rough spots, then the following day did another 6oz over the top, I would be OK.

The reason I ask is because I have been messing with multiple resin tints and pigs and would like to find a way to get more complex hues.  

I ask because I’ve noticed that after I finish glassing a board top/bottom I always get the coolest blends on the floor of the bay where the colors dried over another color. 

Thanks for the original question fresh, unfortunately I’m still too green to help

Steve

Assuming you do everything correctly, yes, you’ll be okay. Poly, no problem letting it set then glassing over. With epoxy, you may want to scuff between layers of cloth just to be sure adhesion is good. I think most important is getting resin to cloth ratio right which should keep the weight down.

Not related to the glass schedule you’re using, but it may be easier to get the resin/cloth ratio right doing one layer at a time than a triple 4 done all at once with epoxy. 4 oz really wants to hold resin with its tighter weave.I generally do double 4 bottoms and triple 4 decks on EPS in single layups both to save time and for less resin waste. When I learned to glass, we were doing 6-4 decks (poly) because the 6 oz was easier to get the resin out of and didn’t really add much weight over a double 4 deck.

Hey  surfthis, thanks for the info!

 

Steve

any problems getting a 2nd layer of cloth to spread nicely over a recent lam?

 

I have done it with fin panel layups, (and recently with glassons) and it is easier to get the 2nd layer of cloth to lay nicely when the lamination is still tacky. It lays perfectly flat, and when the next layer of resin is applied, and pulled through the cloth with the squeege, the glass doesn’t move at all.

hmmmm, maybe I’m seeing this wrong, but I’m picturing a monster clusterf**k trying to pull, then position a whole surfboard length of cloth onto even a slightly sticky poly lam below. plus, the smallest sharp/hard edge will catch the cloth

Hey Bud.

I put the last layer of cloth onto  the sticky freshly wet out lam. layers below…

Lay the last layer on the dry blank before starting any lamination, position it evenly, and trim to size alowing for laps, smooth it out on the blank then neatly roll it back up into a “tube shape”, after first layers are wet out and secured, un- roll the  final glass  layer back onto the board in the same spot you removed it from earlier ( nose or tail )…

If you have your cloth on  a suspended roll at the end of the board, you can un-roll the piece of glass with it hovering over the board and let gravity do the rest…

I have more time with epoxy, still no re- positioning required , never used poly, so I don’t know about the time frame constraints…

hi kite im by a long way no expert on here but from what ive read on other posts i think bud might be refering to the fact that if you lay the glass on a tacky lam you cannot pull the fibre any tighter than the way gravity takes it no matter how you lay it down whereas if yo lay glass on a non tacky board and squeegee the resin out properly you are in effect streching the fibre which adds tension and therfore more stregnth, and also i guess less resin.

feel free to correct me if im wrong

Yaar43 was asking if seperate layers/seperate resin batches could be
done. I’d rather do 'em all at once. However, I’ve done quite a few glass jobs where I put a layer of 4 oz down, let it set, then glassed a triple 4 as usual, just because 4 layers of 4 oz is difficult to saturate then squeegee back out without leaving to much resin in the cloth or drying it out too much trying to get the resin out.  

It’s commonly done
over color jobs where there’s an inset layer on the deck of a bottom
cutlap of a different color. The glass that’s set up doesn’t grab the
cloth as much as you may be thinking.