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new name need for plastic peel ply


dust

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OK, i've talked to a coupla new builders on the phone this week and none of them understood the reason for using the "plastic peel ply" method of construction, they just think it is some sort of peel plying

 

I think it needs to be called something else so that it is not confused with "peel ply".

 

Also, maybe the whole description should be in caps so that they will listen to the screaming:scared:

 

Hows about "laminate bagging"

 

enjoy the build

 

dust

maker wood dust and shavings - foam and fiberglass dust and one day a cozy will pop out, enjoying the build

 

i can be reached at

 

http://www.canardcommunity.com/

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Originally posted by dust

Hows about "laminate bagging"

Or PRE [im]pregnated layups/laminates or PRE wetting layups?

 

Or articulating the notion in a very gentle, diplomatic way that if they have read over the procedures and still can't comprehend the process, perhaps they shouldn't be embarking on a project this difficult. :P

...Destiny's Plaything...

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Well, Dust, it appears to me that by using "plastic ply", we get a smoother finish with less sanding, less dust, and possibly less weight. Is that about right? Peel ply is used when something else is gonna be bonded to the part. Is this half way right?

 

I'm still not clear on which parts to peel-ply and which parts to plastic ply.

 

For instance, after laying up over the doubler on F22, the plans say use peel ply and wax paper over the entire part. Well... does that mean this isn't a good part to use plastic peel-ply? I'm just not sure in this case. I have to go back and read all of John S.'s info on plastic peel-ply. Also, some builders claim that they peel-ply the entire plane (as in all the parts). Why would you want to do this? I know they have a good reason.

 

To me its not why plastic ply, but when (we're now possibly using wax paper, saran wrap, clear box tape, clear plastic called plastic peel-ply, and regular peel-ply). I realize that when used appropriately that all these materials can make the build easier... but it'll take me awhile to be at the point where its second nature to know which "ply" to use. But thats gonna be a fun learning curve!!!

Andrew Anunson

I work underground and I play in the sky... no problem

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Ok, no wax paper, i know the plans say it but don't use it, buy plastic coverred butcher paper call wax freezer wrap, but doesn't have WAX.

 

you can always use laminate bagging on flat layups for substancially less weight.

 

The reason some use peel ply everywhere is that later they can fill with no sanding, in other words, no cutting of fibers with sand paper that reduces strength.

 

enjoy the build

 

dust

maker wood dust and shavings - foam and fiberglass dust and one day a cozy will pop out, enjoying the build

 

i can be reached at

 

http://www.canardcommunity.com/

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Well, I was going to suggest pressure bagging because there isn't any vacuum but instead you use the squeegee to apply pressure to the plastic "bag" thus using pressure to push excess epoxy out without letting air in.

 

But I see you already are using "laminate bagging". :sad:

 

Darn. A day late and 1.50 short (inflation).

 

It takes me longer to think of stuff.:o

Back to building... #618 Cozy MK IV

 

My Cozy web pages, courtesy: Rick Maddy... :cool: WN9G :rolleyes:

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How about we do some layups each way. Some with no treatment, some with 100% peel ply, some with 100% plastic peel ply. Zero out the weight of the core material, and you have the weight of the layup. It would also be interesting to compare epoxies to see if there is a weight savings associated with the brand of epoxy.

 

Show a real weight savings, and now you have some data to backup the hypothesis.

 

It would also be interesting to see what a vacuum bagged layup would weigh in at.

 

Anyway, I've got some divinycell, glass, and Aeropoxy that I would be willing to contribute to the experiment.

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Señior slade did that and it showed impressive results and because we sorta did that on the outside of fuselodge with food wrap plastic, don't use food wrap, way too much work, but i can imagine exactly what john is saying and would have definately had i learned of it earlier

 

enjoy the build

 

dust

maker wood dust and shavings - foam and fiberglass dust and one day a cozy will pop out, enjoying the build

 

i can be reached at

 

http://www.canardcommunity.com/

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Here's my take on the use of clear plastic:

 

I've heard it called "poor man's vacuum bagging" because it gives many of the benefits of vacuum bagging without the hasstle or investment. I call it "clear plastic".

 

AFTER you've done the plans (cloth) peel ply in important bonding areas, use clear plastic on top of everything anywhere and everywhere you can. If a compound curve is making the plastic crease and/or bubble, cut the plastic and lay down multiple strips. Don't worry too much if the plastic coverage isnt "perfect". Accept the benefits where you can get them. WHen laying up BID strips, for example, I lay them up on plastic, cover with plastic, squeege and cut them up with scissors. Remove the plastic one side, brush epoxy onto the prepared bonding area then press in place. Then remove the other stip of plastic, stipple & add epoxy as needed, then add a new piece of plastic wider than the strip and squeege (or press with a mixing stick in tight areas).

 

IMHO there are only two post layup materials worth using. Cloth peel ply per plans and clear 4mil plastic. Forget the wax paper, butcher's paper and saran wrap.

 

Yes, I did do an experiment on my lower winglets. I think the weight saving was around 15% of layup weight (not including the core).

 

When using clear plastic be careful not to over-squeege and leave the layup dry. If you see white patches returning, lift the plastic, add epoxy, replace the plastic and squeege again while warming the layup with a hairdryer.

 

The reason some use peel ply everywhere is that later they can fill with no sanding, in other words, no cutting of fibers with sand paper that reduces strength.

This is true when using clear plastic also. I can't see the value in cloth peel ply everywhere. The cloth is pourous and hard to squeege so you can't do the hairdryer / squeege thing and compress the layup to remove excess epoxy and air like you can with clear plastic.

 

The clear plastic technique may not work well with the thicker epoxy brands. The epoxy has to flow under the plastic.

 

Does this help?

I can be reached on the "other" forum http://canardaviationforum.dmt.net

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This helps a bunch!

This post does answer my earlier questions. If the plans say peel-ply the entire part, then do it... period. If not, then it could be a good candidate for plastic ply. If the plans call for wax paper, use butcher or maybe plastic ply. John, sounds like you could make a great calzone now that you've described your newest method to us - the patented "BID Flip". As of now, my plans are to "poor man's vacuum bag", then apply "clear plastic", then "pressure bag" the part, eventually "laminate bag" it, and then finally "plastic ply" the part. Each part. I hope this post doesn't confuse a "newbie" a couple months from now (including myself!) :D Thanks Guys!

Andrew Anunson

I work underground and I play in the sky... no problem

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Sorry If I Offend... it was all written with a smile (just like when I read my plans):D I really do mean it, I have a better understanding now. Thanks Sincerely, Andrew

Andrew Anunson

I work underground and I play in the sky... no problem

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No offense taken, I'm sure. Mike's just winding you up.:)

 

One comment I'd like to add, though...

In the first few chapters the plans say (cloth) peel ply this, and (cloth) peel ply that, etc, etc. After a while the author stops telling you every little detail for brevity and assuming that you've learned which technique to use when. Basically the plans say to (cloth) peel ply wherever a part will be bonded to another part, even if this isnt specifically mentioned in later chapters.

I can be reached on the "other" forum http://canardaviationforum.dmt.net

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I had already done some comparisons on using the plastic and had become familiar with the the sandwich method.

 

I went to the EAA composites course and ended up teaching the method to the instructor. She had never seen anything like that.

 

By the time I was rocking along I had attracted the attention of a few of the class folk.

 

Two of the guys already had there Cozy plans but hadn't started building yet.

Cozy IV project.

 

Redheaded Stepchild of The Canard Community :bad:

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Nathan,

 

Even though you "taught" the class, how did you like it? Sounds like you had the same instructor I had two years ago (She was there last year too when I took the instrument/wiring course. She is a contributing writer for Kitplanes I believe). I felt the class gave a good foundation. It is all I had as to composite experience when my kit arrived in June of 2002.

 

All the best,

 

Chris

Christopher Barber

Velocity SE/FG w/yoke. Zoom, zoom, zoom.

www.LoneStarVelocity.com

 

Live with Passion...

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We had Burt Rutans video, and he had on really cool platform shoes. Cmon now guys, how hard is it to learn glass work, no don't tell, that will dry up my supply of slaves.

 

Enjoy the build

 

dust

maker wood dust and shavings - foam and fiberglass dust and one day a cozy will pop out, enjoying the build

 

i can be reached at

 

http://www.canardcommunity.com/

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While its not that hard, it is an adventure to those who have never seen it done before (ie. me). I am well on my way and feel pretty comfortable with the flat layups I've been doing for the bulkheads so far. But I've just gotten to the IP reinforcing ribs and it hasn't been pretty. I would like to do these over, but since no one is ever going to see them I'm not going to scrap a perfectly good IP on the count of some ragged looking work that will be hidden.

 

I am still debating however, scrapping my front seat bulkhead. This was my first "real" layup and I think there are too many little air pockets. Heeding the mantra that says too much epoxy on the floor is better than too much epoxy on the part, I think I squegeed too hard with this peice. I now have a much better feeling for what a wet layup should look like and how much epoxy I should be using. I also have a better feeling for the amount of time I have with the epoxy. I'm using all fast hardener with MGS 285 and if you work through it at a good pace its not too bad. I think, however that I'll be ordering some slow hardener for the summer and for the large fuse sides layups.

 

The seatback also has a pretty ragged join where the two peices of foam were glued together. I didn't sand this joint before layup so it looks pretty bad. I now know to sand all such joints to get then nice and flat before laying glass on.

 

Another problem with the seatback is that the cloth isn't fully bonded all along the edge of the 45 degree bevel at the bottom. I didn't cut enough of the glass away before cure so some of it curled up. This is mentioned in the education section, but I'm kinda dense sometimes and don't pay attention to instructions until something like this bites me.

 

Actually I haven't been doing the knife trimming stage at all with the layup so far. I tend to leave things the cure overnight so don't have a chance to do it. For flat bulkheads its not a problem as the foam is thin and the glass doesn't have a chance to bulge up on the edges (I've also weighed down all these layups so it can't bulge). But I can see it hapennning for other, more curvy layups. I'll just be aware of it then.

 

All can be fixed, except for the dry layup. But I'm not sure its a dry layup in the first place. I'm going to have to get a local builder's opinion. I guess its these types of judgement calls that scares most people. It's hard to know you are doing it right until someone tells you so.

Rui Lopes

Cozy MkIV S/N: 1121

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The class did give me a sense of security, but it also failed to quench my thirst for an more advanced info.

 

The instructor was very professional but was a kit builder, I think that the plans guys have a greater level of knowledge. She did a good job though.

 

When we did our canard sections, she told the class they could use whatever fiberglass they wanted, she also failed to discuss how to correctly cut or overly certain types of fiberglass.

 

Me and the other Cozy guys teamed up and made sure we did it old school. I used the plastic method on mine.

 

It's interested the plans that they have calls for kevlar on the leading edge.

Cozy IV project.

 

Redheaded Stepchild of The Canard Community :bad:

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Yes, I am using plastic peel ply for all these bulkhead layups.

 

I like the way the part turns out. Its also nice to squegee on at the end og the layup.

 

The main thing is the exprience factor. I find that I really learn only by making mistakes. I can read all I want, but until I actually screw up and see the consequences I don't really know it. I know others are much better at reading something and "getting" it. Unfortunately I'm not one of those.

Rui Lopes

Cozy MkIV S/N: 1121

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Originally posted by cncdoc

...I was going to suggest pressure bagging because there isn't any vacuum but instead you use the squeegee to apply pressure to the plastic "bag" thus using pressure to push excess epoxy out without letting air in.

The opposite of vacuum is pressure.

 

Keeping in context with 'vacuum bagging', pressure bagging strikes me as the most comprehensive and self-describing phrase thrown about. Sylabbically :D, pressure bagging fits:

 

vac-uum bag-ging

press-ure bag-ging

Let's see how democratic we can be with this... :grouphug:

Jon Matcho :busy:
Builder & Canard Zone Admin
Now:  Rebuilding Quickie Tri-Q200 N479E
Next:  Resume building a Cozy Mark IV

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said by RUI

 

I know others are much better at reading something and "getting" it. Unfortunately I'm not one of those.

 

 

No, I disagree, we all learn by doing and we all screw up a little anyways. Thats one reason everyone likes glass, it's easy to fix a screwup.

 

enjoy the build

 

dust

maker wood dust and shavings - foam and fiberglass dust and one day a cozy will pop out, enjoying the build

 

i can be reached at

 

http://www.canardcommunity.com/

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When we did our canard sections, she told the class they could use whatever fiberglass they wanted, she also failed to discuss how to correctly cut or overly certain types of fiberglass.

 

 

OK

 

BID - almost always 1" overlap

 

UNI - Almost always butt joint, but always keep length fibers continious. you can't lengthen UNI, only widen it with a butt

 

it is that simple

 

enjoy the build

 

dust

maker wood dust and shavings - foam and fiberglass dust and one day a cozy will pop out, enjoying the build

 

i can be reached at

 

http://www.canardcommunity.com/

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