​Peel ply/wax paper/plastic wrap experiment?

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I want to duplicate an experiment I tried years ago - laying various plastic wraps, wax paper and other releasable materials atop resin. There were a couple of problems with that experiment - one, it was so long ago that I was probably using polyester resin, and two, I don’t remember the results.

I used four different types of plastic wrap, Saran Wrap, Cling Wrap, and…I forget. I do remember that two of them were kinda stuck, and that Saran Wrap was one of them.

I want to try that experiment again, using the various plastic wraps, wax paper, peel ply and etc, but this time using West System 105/206 on one batch and G\flex on another. I might try it first using just the 105/206; I hate to waste G\flex, and I could repeat the experiment using G\flex on only the release materials that proved to work with regular epoxy.

For the test bed I’m thinking about epoxying a scrap pieces of fiberglass cloth to a (clean and alcohol-wiped) length of vinyl siding, covering those “patches” with the various release materials and weighing the patch down with a large zip-lock bag of sand. Peel off the plastics (or maybe not) a day later and see what happens.

I’ve got plenty of scrap fiberglass cloth, epoxy, peel ply and wax paper and just need to pick up the various plastic wraps.

Any idea which plastic wraps are used in epoxy application successfully?

Or other commonly available plastics? I’ve heard that Xerox transparency sheets work, if only for flattish areas.

Any suggestions for changes in the experimental methods or materials?
 
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Why not just spread a layer on the different materials you want to test?
 
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Mike, Sorry I don't have any suggestions but I do follow these fabrication ideas that you post, but on this one I'm lost. Why in the world would you want to place all this plastic stuff on top of your of your resin? Even if you could get it off later the resin would still be set up right? Now my only experience with fibre-glass was a catastrophic failure so I'm nobody to judge, I'm just curious.

Best Wishes, Rob
 
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My experience with plastic wrap and an unknown resin ( were installing skid plates long ago) was wrinkles in the surface of the finished product.. Peel ply applied to a kevlar patch infused with polyester resin resulted in a smooth edge.. Kevlar gets wild and pointy without something smoothing it out at the edges which is what plastic does..

My bet is on peel ply having the nicest finish. And wax paper having a mess.

Seems today is a nice day for such inside projects. July 4 and its raining ..so far in the last 2 days eight inches of rain. And rains from Arthur for dinner..will rain all day..
Got company and a fridge full of lobsters .. aargh.

Oldie Moldy, why did you send us some moldy weather?;)
 
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Why in the world would you want to place all this plastic stuff on top of your of your resin? Even if you could get it off later the resin would still be set up right

Rob, I guess I neglected to mention the “why”.

In some instances of glass and/or epoxy boat work it is helpful to use a release fabric/material atop the patch or outfitting. Examples:

Using epoxy to adhere a loose or broken flap of material. I use sandbags to weigh down anything that might lift as the epoxy cures, and I’d rather not glue a sandbag to the hull.

Working with seamed edge fiberglass tape (which isn’t actually “tape” with an adhesive edge but rater just strips of cloth with a seamed edge which doesn’t fray). The seamed edge of glass tape stand tall and sharp when coated with epoxy. And I mean tall and sharp enough to slice a finger or leg. Pressing some releasable material atop the tape completely eliminates that sharp raised seam edge without any need for sanding.

Dynel cloth when wet out with epoxy cure to the consistence of 80 grit sandpaper. Again, that can be eliminated with out the need for sanding.

When installing D-rings I place a piece of wax paper over the D-ring and weigh it down with a sandbag so that I don’t inadvertently adhere the weight to the hull with any excess Vynabond or epoxy. Same goes for anything that might lift when the adhesive is setting up.

My experience with plastic wrap and an unknown resin ( were installing skid plates long ago) was wrinkles in the surface of the finished product.. Peel ply applied to a kevlar patch infused with polyester resin resulted in a smooth edge.. Kevlar gets wild and pointy without something smoothing it out at the edges which is what plastic does..

My bet is on peel ply having the nicest finish. And wax paper having a mess.

Kim, my go-to has become peel ply for a number of reasons. The faint weave left by peel ply is much easier to sand off than the crinkles and ridges I often get when using plastic wrap or wax paper, and that faint weave is helpful for mechanical bonding if an additional coat of resin is needed after curing.

Peel ply eliminates amine blush (the blush rests atop the peel ply, so it is mostly gone when the ply is removed). Peel ply (or any other releasable material) will flatten the raised, razor sharp edges of fiberglass tape.

I know peel ply works best in most applications, and that it blessedly eliminated a large amount of after epoxy cure sanding (and boat work seems to be 20% prep work, 20% actual epoxy application and 60% sanding).

But I doubt that many shade tree boat tinkerers have or use peel ply, so discovering which plastic wraps or other commonly available grocery or hardware store products work best may be helpful.
 
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What about something like a 6 mil plastic used for vapour barrier in a home? Heavy duty plastic wrap.

Beyond easy availability the advantage of plastic food wrap is that it stretches some and will conform to complex curves. For installing something like a skid plate, where the stem application area is curved in longitude and latitude, that stretchability is advantageous.

Or at least it is said to be advantageous; my results trying to use plastic wrap on complex curves has been less than ideal – I always end up with a few jagged crinkles and creases.

Peel ply will conform some, especially if cut and laid on the bias.

I may add some plastic sheeting to the test materials anyway; I have plenty in the shop.
 
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Rob

I use sandbags to weigh down anything that might lift as the epoxy cures.

Thinking about that I use a lot of stuff other than just the shop sandbags , which are nothing more than gallon and half-gallon sized Zip-Lock bags filled with sand (really handy in the shop, and they lasted quite a while).

I use clamps. Lots of clamps, and all manner of homemade jigs and rigs, some customized for a particular boat issue.

I have some custom warped and bent pieces of wood in the shop that conforms to a variety of hull curves. I can usually find some way to clamp things down or together, even along a curve. Even thin scraps of Lauan will take a minor curve. Sometimes the critical issue, especially in hull repairs, is to press things together or line things up, and hold them that way while the epoxy sets.

The more complex clampage jobs may involve a sandwiched-layer of: curved wood backing (so the clamp has something firm to draw tight against)-foam pad/minicel scrap (to help the conform to the curve)-wax paper (so I don’t glue stuff to the boat)-hull….wax paper-sleeping pad scrap-wood block backing.

I wish I could find the photos of the busted Dagger Caper we repaired years ago. Really busted, as in torn almost in half, through one gunwale and down to the chines on one side.

In order to get the torn edges of the hull held back together we had that thing restrained half way to Sunday. We had the hull upside down on sawhorses, with a car jack off the floor pressing a length of 2x4 to hold the busted hull upwards, another jack and 2x4 atop the hull up to the ceiling beam to press parts of the hull downwards and a twisted loop of rope run between the carry handles, turnbuckle tightened just so using a length of wood in the loop.

Other weights, clamps, ropes and jigs along the hull. We just kept tweaking the hull alignment until we had it perfect.

It looked like Frankenhull in the shop, and it would have looked really odd on the water with all that stuff glued to it.
 
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Beyond easy availability the advantage of plastic food wrap is that it stretches some and will conform to complex curves. For installing something like a skid plate, where the stem application area is curved in longitude and latitude, that stretchability is advantageous.

Or at least it is said to be advantageous; my results trying to use plastic wrap on complex curves has been less than ideal – I always end up with a few jagged crinkles and creases.

I've used clear plastic wrap on skid plates. It may be stretchy but I never noticed. It does fold easily, which enables it to wrap in both direction. Yes, it leaves a bit of crinkles, but that's easily taken care of after the epoxy is cured.
 
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The experiment and results.

The best test bed I could find was a scrap piece of vinyl siding, which will stand in nicely for the vinyl skin of an RX canoe. I wish it was something with more complex curves to test the “stretchability” of the plastic wraps, jut it’ll do. More on the usefulness of stretchability later.

I’m mostly curious to see which if any of the top films end up adhered to the epoxy, to see how the films flatten the would-be razor sharp seams that stand tall on fiberglass tape and how each smoothes out kevlar felt (which, I know, is a crap material, but it’s still what is included in most skid plate kits).

I’ve got bags of scrap glass tape and kevlar felt. Know I know why I kept it, and any other potentially usable piece of scrap material. It’s not that I’m cheap, it’s that I’m, um, experimental, or some subset of syllables therein.

I do have a couple of harder-to-come by films on hand; peel ply and a roll of mystery labeled “Porous Release Film” made (I think) for vacuum bagging. I’m going to omit some other “films” that have good reputation but limited availability - lexan film, Xerox transparencies sheets and etc

The films:
Saran Cling Plus
Glad Press & Seal
Glad Cling Wrap
Reynolds Wax Paper
Porous release film
Peel ply

The vinyl siding bed has been scrubbed clean, dried and alcohol wiped. Time to cut some fabric and film, and mix some epoxy.



The Test: I painted a coat of epoxy (West System 105/206) on the vinyl siding, laid down pieces of kevlar felt and seamed edge glass and filled the cloth with an additional topcoat of epoxy resin in each test bed. I laid on the test films, smoothed each out with a gloved hand to eliminate what wrinkles I could and then rolled each film, pressing down with a short nap roller.

I weighed the “patches” down with Zip-lock sandbags, but removed them from the peel ply and (visibly perforated) porous release film while the epoxy was still green.



I could immediately confirm that I do not like working with stretchable plastic wrap. I can barely get kitchen leftover containers covered without ending up like a transparent and frustrated mummy, much less achieve a smooth and wrinkle-free film atop epoxy and cloth.


If there’s a trick to using stretch wraps atop epoxy and cloth it needs more than two hands.

I removed the sandbags atop the peel ply and porous film after 4 hours, which was almost too long. They were starting to get stuck and just barely came off without tearing open the Zip-locks and dispensing sand on the test bed. I live in trepidation of that happening when using sand bag weights.

Results:

I left the various films on for 12 hours before pulling them.

All of the test films knocked down the seamed edge of the tape and smoothed out the kevlar felt. The glass was barely visible and the loose end strands disappeared completely, with no stray frays poking up like composite lancets, and the cut sides of the kevlar felt were beveled smooth along the edges and not standing abrupt. So far so good.

Saran Cling Plus – It released cleanly except for one small shard of Saran that was trapped in a wrinkle. The resin was hardened, but there were many (many) sharp wrinkles and crinkles that would necessitate a lot of sanding. Not a pleasing surface.

Glad Cling Wrap – Identical to the Saran Wrap in every way.

Glad Press and Seal – Far smoother with less wrinkles and crinkles than the previous two, but the resin still felt tacky. It either needed more cure time or that tackiness was sticky residue from the Press and Seal. I set the test panel out in the sun for a few hours and the Press and Seal test piece was even stickier. I’d guess that stickiness is residue from the top film. Nix that one - Press and Seal is best avoided for epoxy work.

Reynolds Wax Paper – The cleanest release and smoothest epoxy/fabric surface of any of the grocery store products, with only a few small wrinkles/crinkles. I didn’t see or feel any waxy residue, but I’d want to lightly sand and clean that area just to be sure; wax would be a horrible contaminat to leave in place before topcoating.

Peel Ply – As expected the best of the lot and the easiest to work with, leaving a very faint weave pattern from the peel ply fabric. No wrinkles, no crinkles baby butt smooth.

Porous Release Film – Very clean release, but the epoxy surface is almost as wrinkled as with the two “cling” plastics.

Summary:

All of the materials released after a 12 hour cure, with one wrinkle trapped shard. In the previous plastic wrap experiment years ago (using poly resin) I had clamped the films down and found a good bit plastic trapped in compressed wrinkles and crinkles, especially with the Saran Wrap.

For a flattish surface or a simple curve wax paper seems to be the best, or at least easiest to work with, of the grocery store products. However wax paper will leave sharp-edged pockmark voids if the area is at all resin starved and will wrinkle if “forced” to take too much of a curve.

For complex curves one of the stretchable cling products “might” work if laid in place with four hands stretching the material smoothly across the surface area. Or not, even taping down one side I have never had much smooth success trying to stretch plastic wraps, and the resulting wrinkles and crinkles were more of a PITA to deal with than using no release material at all.

Clarification: While the cling products “might” work with better stretching technique on the outside of a curve (ie canoe stems), on an interior curve like the chines plastic wrap would be a wrinkled and creased disaster to get into place. Wax paper would be easier to apply in that application.

The mystery “porous release film” (a reddish-translucent film perforated with small holes) was no better than the cling wrap plastics. I’m guessing it was intended for vacuum bagging.

Peel Ply – If you do epoxy work get you some.

By far the smoothest finish, wrinkle and crinkle free. The faint fabric weave sands far easier than jagged wrinkles and crinkles, and makes a beneficial mechanical bonding surface if left in place for additional epoxy coats. Cut on the bias or laid in multiple overlapping sections peel ply will wrap a stem curve, and it’s much easier than any cling wrap for working inside a hull.

The peel ply removes most amine blush, and I think some excess resin as well. I can’t prove this, but after using peel ply for a few years I have a feel for the least amount of resin necessary to fill the cloth, with any small amount of excess coming off with the peel ply.

Ah well, in for a penny, in for a pound. Before I put a year’s supply of plastic food wraps in the kitchen cupboard I’ll try a small test area using G\flex with each product to see how that sticks-to-damn-near-everything epoxy releases from the various films.

And if I feel energetic in a week or so I may try sanding down the wrinkles and crinkles to gauge the effort required, and topcoating with more epoxy to see what’s needed for a smooth surface.
 
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Mike, I applaud your deliberate and rational approach. It's the kind of thing I might do if I had more patience. I have just one question: what's Peel Ply?
 
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Mike, I applaud your deliberate and rational approach. It's the kind of thing I might do if I had more patience. I have just one question: what's Peel Ply?

Gavia, I just like to satisfy my curiosity playing in the shop. Especially when it is Mid-Atlantic hot and humid; the shop is one of the few rooms in the house with AC.

Peel Ply:

http://www.clcboats.com/shop/product...se-fabric.html

Friend Pete on another board noted that "“I have used a close weave, untreated nylon cloth sold by Sweet Composites as peel ply many times. It is relatively inexpensive, but as Charlie indicated, it needs to be removed when the epoxy has cured to a green state. If it is left on too long, it can be difficult or impossible to remove”".

Since I often pull the peel ply while the epoxy is green (to topcoat, or simply to get underneath and remove tape and paper dribble perimeters) the release-treated peel ply is unnecessarily expensive in that application.

I’ll be ordering some untreated nylon cloth from Sweets so I can use either release treated or untreated as the application demands.

http://www.sweetcomposites.com/Polyester.html
 
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G/flex release film results

Almost exactly the same as with West System 105/206. All of the “films” released (although the upside-down Press and Peel was stuck pretty well) and the wrinkles, crinkles and folds in the cloth and epoxy below were identical to using 105/206.

I didn’t learn a lot in this experiment. All of those products work to some extent. I wouldn’t use Press and Peel, and my cling wrap technique needs work to achieve a smooth surface. The perforated wet bag release film I have is useless for my purposes. Using G/flex, or a mix of G/flex and 105/205 works equally well with all cover materials.

I’ll stick with wax paper for simple flattish patches and peel ply for the rest. And pick up some untreated nylon cloth from Sweet Composites for green epoxy pulls.
 
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....I’ll stick with wax paper for simple flattish patches and peel ply for the rest. And pick up some untreated nylon cloth from Sweet Composites for green epoxy pulls.

That's where I've settled, too. I do use cling wrap when making small parts such as carbon fiber padeyes for kayak hatch lids and gear lash points. These do not require a smooth finished surface and its rather easy to make good ones with the cling wrap as it conforms nicely to the half round dowel molds.
 
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I know this is an older thread, but was just what I'm into now. Where Was I !!
Thanks Mike and Alan for bringing me around to it !

Jim
 
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If you are using peel ply for the first time, or ordering it for the first time, know that there is a difference between “green release” peel ply, like the nylon stuff Sweets sells, and release treated peel ply (Express Composites and others).

The green pull stuff needs to be removed before the resin has set, and that time window varies with temp and weather. The release treated stuff can be pulled hours (or even days) later.

The green pull stuff may be useful for applying a second coat with more chemical bond, but if you wait just a little too long it can be a two handed foot-against-the-hull struggle to pull off, and last time I looked the cost was the same.

I’m probably missing some peel ply education. In what applications is green pull peel ply advantageous?
 
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Probably none as we found on the Caddilac build, the green that is. That stuff has skunked me once and I'll only use in dire situations seeing how's I have almost 2 yards of the stuff! I mean it does work but you have to be on top of the time game to make it work! Anyone want some? ;-)
 
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I use release film, it works great!! If I wouldn't have draw the shape I wanted with a sharpie, it wouldn't be noticeable(other than the tiny little bubbles... It was my first time using it)!! chttps://www.youtube.com/watch?v=Xm2Ezo70vFI
 

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