PEEL PLY FOR ALL VAC BAG CORK????

General Discussion
1

After a few cork boards with no peel ply and the 3 dozen plus boards using peel ply, gotta say peel ply is the way to go.

Benefits include:    most, if not all, unecessary excess resin wicked off. No tape sticking to cork if used to hold down skin. Ease of removal of peel ply to bonded cork skin. No sanding necessary for glassing on flats, cork ready to go. Ease of placement during vac bag process.

Down side: 5-10 dollars expense of peel ply depending on length and width of board.

 

Haven’t used peel ply on a regular basis for decades. I conclude with cork it is the best way to go.

 

 

 

2

BB30,

got a question do you wetout the internal glass on a wetout table or you did it on top of the blank? im planning to vacuum on the corecork this weekend but dont know if i should wet out the glass on top of the blank or do it on a wet out table.  and also about what vacuum psi are you pulling? thanks for the help.

3

9’6" x 32" wide . bottom pull 1.3MM NL-20 corecork, peel ply freshly taken off.

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4

Have you tried an outline shaped piece of polyethylene ? I use PolyEthylene garbage bags instead of peel ply because the PE is very thin so I get a wrinkle free mirror finish and it allows the air and resin to flow to the air egress point.

 And because garbage bags are pennies to buy or pick up. If youre in Oz I’ll send you some…

5

Great Idea but I am looking to wick excess resin off my cork and the peel ply does the trick. I will do a hand lay up glass job over the cork skinned board. Thanks for the offer.

I live in the USA. If I lived in AUS I would have a speedneedle quiver, call it a day and not bother making boards.

aloha,

Charlie

pic below of example of no peel ply used. Notice the shiney resin on cork. I believe peel ply will make it lighter, as strong, make less work prior to outer glassing.

 

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6

A lot of guys say peel ply is not necessary.  I disagree.   It’s just another important tool in the bag.

Look at the frozen epoxy / pre-preg thread. There are ways to do without the peel ply.     Pre-preg being a step in that direction.

I like the bonding surface peel ply leaves on the finished core or laminate. . Ready for hot coats and such right out of the bag with little or no sanding required. I  also like the way it draws out excess resin.

I’m guilty of  buying the expensive stuff at the composite stores , but you can find very good  substitute peel ply at the local womens fabric supply warehouse… You look for the bargain bin nylon rip stop type of peel ply for less than half the cost of the stuff they sell at the composite shops.   It’s slightly harder to tear off of the laminate beacuse it’s not surface treated like the high priced composite specific peel ply.    You just make more razor cuts in the nylon which makes it easier to peel off of the laminate.

Terry towel pajama fabric material makes for great breather material as well.    The Flintstones motif rates double bonus points…

VH.

PS. Look at most resin infusion jobs, Peel ply is used to help distribute epoxy as well as absorb excess resin.

7

Do you use a wet out table? I vacuum D cell skins, with no bleed out.

8

VH,

 I quess I posted this because I would consider this an off label use of peel ply. Unlike the use of peel ply directly to a fiberglass cioth vacuum bag situations. I agree with you that there are ways to do with out peel ply.  But for core cork situations peel ply is perfect. I haven’t read the frozen epoxy thread but prepeg is standard use in OC type canoes and crew boats. Doesn’t even need to be frozen because the epoxy formula is not activated until the vac mold is heated in the oven. 

I never use or would consider using peel ply with a full on wood laminated build. It is not necessary.

70 cents per foot x 5 feet wide. I think that is cheap for the ease of use. Never used the bargin bin nylon stuff you mention. If it peels off with difficulty it would not be worth it to me with the corecork. For other applications it might be worth the small savings. 

9

Yes I have a wet out table. A craigslist pingpong table that folds up nicely.

The glass cloth on the cork skin acts as a wet out table, so I am not wetting out the glass seperately then applying to the cork. I also don’t glob on the epoxy.

D-cell and corecork are apples and oranges.

D-cell is 5 lb density and the thinnest I have used is 1/8". You have no leak through because it readily absorbs into the d-cell and you hopefully had a good wet out. The problem of absorbtion still exits when you do the topside with a hand glass job or did a full top and bottom vac pull which you probably didn’t because you are aware of bleed outs.

The NL-20 corecork is 12.5lb density and this was 1.3mm and getting toward paper thin. It will not absorb the epoxy as readily as d-cell, but the nooks and crannies in the cork will be filled with resin. This is my goal actually.

The boards that have the resin shinny stuff on the outside of corecork with my first few builds, sands off easily but is like scabby flakes of epoxy skin. It is of no use for strength. but is just added weight and effort in removing it.

Peel ply is super effective in acheiving perfect resin free outer skin but the micro nooks still being filled.

My wet out table is used for pretty much for 1 specific glass cloth/foam build(non vacuum bagg) I do for one customer.

I personally think corecell HD foam is a bit better than d-cell for lighter final product.

 

10

I’ve not used the core cork yet bb30,this is good stuff though thanks.

11

Fiberglass Hawaii just stopped selling Corcell, and switched to d-cell.  Corcell was much better.  I wet out on plastic sheeting.  then put it into the skin.  You can't wet out onto d-cell because it soak up too much epoxy.  Now here's the tip,  Cerex, not glass between the skins.  $.40 a yard instead of $4.00  also it really holds the epoxy until the vacuum squeezes it out.  No peel ply needed, because it holds the epoxy so well.  Then add some fiberglass where you want to stiffen the board.  Engineered flex

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12

 

I am a definate follower and self proclaimed disciple of this stuff. If I could give you one piece of advice about corecork to you it would be…

if you can only afford 1 roll, I would get the NL-20  1.3mm or 1.5mm thickness. I have gone through 2 1/2 rolls of the 2mm and it is awesome, but after starting in on this 1.3mm thickness I think the 2mm is overkill on the builds. Just pulled the board above out of the bag with 1.3 all the way around and it is super light and rock solid. Put all the deck patches under the cork and this board will be fully glassed with no exposed cork. If you have exposed cork just double up the cork on the deck to get a thicker and softer deck for traction.

If you are vac bagging wood planks and veneers now this stuff will blow you away.

13

I guess I am on track since I want a stiff board I am using fiberglass under all the cork. Unless you have used cerex under cork I think you might be making a big claim on no epoxy  bleed through. cork is as far as you can get from d-cell/corcell in cost ( 1/6th the price) and physical properties(density,flexibility),how you store, and ease of use to name a few. I never used peelply with HD foam.

My deck came out perfeeeeecccct with the peel ply once again and the microfill of resin in the cork, due to the peel ply, is beautiful. I took a pic but it just looks like a brown board. Already slapped the vent, handle and leashh plug in and will do the 5 fin boxes tomorrow. They almost build themselves. Super light with the 1.3mm NL-20 corecork.

I would like to use cerex someday. I have looked for it in my shop, but with 5 woman in my household, the closet I came to cerex was an empty box of kotex.

My next unusual material build will be Jute weave bottom and cork or wood deck. Going for the oldest materials known to man build.

14

No, I’ve never tried cork.  I thought the price was similar to D-cell.  Two boards out of one $50 sheet.  So it adds $25.00 a board.  How much does cork cost?  Is it heavier than D-cell?  I think cork is about 2 pounds per cu ft more.  But then again, I’m not looking for super light.  As long as my builds come in lighter than a conventional PU PE board.

You can buy Cerex direct from the factory by the roll, or smaller quantities from Graphite Masters.  My 250 yd roll direct from Cerex was about $120, tax and delivery included.  Just make sure you only by the N-Fusion line.  They all fuzz if you sand into them, but the others seem worse.

15

230 dollars of core cork would be about 1500 dollars od d-cell at your price you quote.  You must be making very small boards or not covering the whole board if you get two boards out of one sheet of d cell.

Saw the cerex storage requirements.     No thanks.

cork storage? You can do it any way that cerex is not allowed.

Did you know peel ply will solve your fuzzy problems with the cerex?

Guess peel ply just isn’t for cork.

16

I only cover the deck.  Deck and bottom is too stiff.

Not peel ply with cerex, but release film and a wet out table.  Never hand lam with it!  Soaks too much epoxy.

Lay out your cerex,  lay out your cloth,  wet it out.  Apply to board. Vacuum.  No fuzz.  But if you sand it, fuzz.  Your release film needs to be tight and perfect, because cerex wont drape, and will fight you on the rails, and lift up when you aren’t looking.

17

I didn’t find anything about that.  What do you know?

18

1mm NL-20 corecork is 25 cents per foot and that is 4 feet wide. A 2 dollar piece is the equivelant of your sheet of d-cell at 1mm thick and a 4mm thick sheet would be around $6.50 for the same size sheet.

Peel ply solves draping issues and the release film protects your vacuum bag. You can squeegee perfecly smooth the peel ply and tape overhangs to each other. for a smooth tight fit. The release film at that point just need to be smooth so your desired finish does not have wrinkles in it. I can’t quite get my head around any fuzz possible if it is under fiberglass cloth??? Sounds like you are doing things the hard way?

 

Below are the storage requirements of cerex. 

**I. INTRODUCTION**

Cerex Advanced Fabrics, Inc. produces a wide variety of products to satisfy even the most demanding application: SpectraMaxTM, Cerex®, PBN-II®, OrionTM, Spectralon®, and Vibratex®. Cerex® nonwovens are tough and durable materials packaged to withstand the wear and tear of a typical manufacturing site. However, as with any other manufacturing material, nonwoven rolls should be handled with care and stored properly to ensure that the material properties required for an application are retained. In general, Cerex Advanced Fabrics, Inc. recommends that Good Manufacturing Practices (GMP) be utilized when handling Cerex® nonwoven rolls. Specific recommendations by Cerex follow. When proper storage and handling practices are followed, there is no shelf life limit to Cerex® products.

**II. SITE LOADING AND UNLOADING**

All Cerex® nonwovens are delivered in a protective wrap. A forklift or front end loader fitted with a tapered pole is recommended for loading and unloading nonwoven rolls. The pole should be long enough to extend at least 2/3 of the way into the roll core to avoid the possibility of buckling or breaking the core. In some cases, nonwoven rolls may be packaged on pallets or in boxes. Good forklift handling practices apply to these palletized materials.

**III. SITE HANDLING**

Nonwoven rolls should be lifted off of the ground when moving. Dragging rolls is not recommended. It is recommended that Cerex® material be staged in the processing areas 24 to 72 hours prior to processing (unpackaged if possible) to allow the nonwoven media to acclimate to the process area temperature and RH conditions. Care should be exercised such that nonwovens be protected from all sources of contamination, including oil, grease, dirt, and water.

**IV. ON-SITE STORAGE**

During storage at your facility, nonwoven rolls should be protected from moisture, direct sunlight, snow, and vandalism. Therefore, Cerex® product should always be stored indoors, under proper covering. It is preferred that the media be stored in a climate controlled environment where possible. The protective wrapping should not be removed until the nonwoven is ready to be staged in the processing area. Vertical storage should be avoided where possible. Care should be exercised during roll goods stacking to limit the height and to provide adequate chocking.

**V. ULTRAVIOLET LIGHT EXPOSURE OF CEREX****® ****NONWOVENS**

When left exposed to ultraviolet light, all nonwovens slowly degrade, losing strength in the process. It is highly recommended not to expose Cerex® nonwovens to direct sunlight prior to use.

**VI. PROTECTING CEREX****® ****NONWOVENS FROM MOISTURE AND WATER**

Polyamide based nonwovens readily absorb moisture. In the case of our PA6.6 based materials, moisture uptake can effect a dimensional change to the product. As a result, you may experience a loosening of the package as RH increases in the storage environment. Conversely, low humidity conditions can tighten the package formation and may cause the product to shrink in both the machine and cross direction. Controlling the humidity during storage will minimize dimensional changes. Protective covering on the nonwovens should not be removed until staging in the processing area.

 

 

 

19

Hard way, definitely!

My thinking is, don’t apply more epoxy than you are going to use, and use all the epoxy you apply.

Wet out table keeps the core from soaking it in.  Cerex absorbs more than it needs, but that is your reservoir for later.

Once your desired lamination schedule is saturated, and all extra epoxy has been removed, place it all on your core.  There should be of layer of Cerex on the surface.  There may be more below, depending on your own engineering.

When covered in release only, and placed under vacuum, Just enough epoxy is forced into the core to bond.  And just enough is forced to the surface to skin.  If done right, you get a hotcoat smooth surface, with no fish eyes etc. 

Don’t sand this surface, or you get fuzz!

Then apply the thinnest finish coat of either poly resin, or Fiberglass Hawaii Fast (but not the thick and fast) epoxy.  Sand that surface starting with 220 or finer.  If done right, just minimal sanding.

Way more difficult than just a regular board, but you are getting a fiber infused, perfect hot coat, with less epoxy than a normal simple hot coat.

20

i personaly think corecell and d cell are poor materials for surfboards. but if you must use it and want to use less resin on outer skin you can roll the resin onto stiff plastic . cloth on that and then the corecell layed on that then bag it. you can can very low ratios with this method and no excess on the foam cells. balsa doesnt  absorb much resin at all. balsa has lowest weights so far ive seen even with a standard layup. i think with cork i like charlies idea of getting it between the cells . weight is a non issue for surfboards IMO. marketing bs. most low income surfers should be concerned with durability and not fall for marketing hype. and in that regard materials like cork and wood should be used to that advantage.  natural materials are the way to go where posible.