Sources for Lexan?

I know I saw a thread recently about what thicknesses and where people get Lexan, but I can not find it for anything at the moment.

At most It will be used for rockets that are 24mm powered. Maybe a 24mm cluster but that is unlikely. I was thinking on the order of 0.020" - 0.030" would cut it. However all I could find at Home Depot was 0.093", and 0.110"

So where is better to look for smaller thicknesses?

Is 0.020" - 0.030" good for most 13mm to 24mm rockets or should I consider down to 0.010?

Thanks for the help

https://www.micromark.com/Plastic.html


They sell 0.030" thick polycarbonate--Lexan is a trade name for polycarbonate.

You can get 0.03, 0.04 and 0.062 at www.smallparts.com. They call it polycarbonate sheet.

First: BE WARNED!!! the stuff at Home Depot is NOT a polycarbonate of any kind...it is a modified acrylic. REGARDLESS OF what any of the floor sales people are telling you. Neither HD or Lowe's stock or sell Polycarbonate sheet as stormwindow/door replacement. This information come directly from both companie's Central Purchasing Office. NEITHER PURCHASE Polycarbonate!
Ask one of the Associates to bend a piece of their material 90° without snapping it...they can't and most likely will not try.

To more properly answer the Question:
You can get just about any thickness Polycarbonate, " Lexan or Tuffak" from you local Sign Supply warehouse or Commerical Plastics Distributor, Look in the yellow pages under "Plastics". Some of the Industrical Supply Houses like McMaster-Carr also sell Polycarbonate in sheet, but it is ALWAYS much more expensive and you'll have to pay for shipping as well.

For Most 3 to 5 D12, MPR models .063" (1/16") is adaquate depending on fin Span. .040" and below should be using on smaller models with shorter spans.
I use a lot of various size Polycarbonate on Upscale clusters, and Odd-Rocs Hope this helps.

There are many places online selling Lexan sheets. The place I ordered from is https://www.estreetplastics.com/. Pricing and service were good.

-- Roger

Here too.

https://www.usplastic.com/catalog/item.aspx?itemid=22929&catid=704&clickid=searchresults

If your fin pattern will fit within a CD use that. A CD is made from almost pure polycarbonate.

I have a question, what is the best way to cut Lexan? Can I score it and snap it like plastic or does it need to be cut all the way through?

Bunsen Honeydew said:

I have a question, what is the best way to cut Lexan? Can I score it and snap it like plastic or does it need to be cut all the way through?

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Yes, I bought a scoring knive at Lowes and just a couple of passes I put the piece over an edge and easily snapped it with a very clean cut.

I have to disagree with "micro" at least here in Florida. I was able to buy a few sheets of real Lexan XL10 at Lowes.

For smaller rockets, the clear and much cheaper acrylic has worked fine and is even easier to cut.

Did you know that Lexan no longer is owned by GE? It was sold in 2007 to a Saudi owned company SABIC (Saudi Basic Industries Corporation).

jderimig said:

If your fin pattern will fit within a CD use that. A CD is made from almost pure polycarbonate.

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FYI:
Lets try to be careful not spreading false or misleading information please.
Not all CD's are alike, and NONE are "Pure Polycarbonate" they are all a laminated manufactured form of polycarbonate and other materials. Some are quite brittle and shatter when flexed while some can be tougher to break. However even the hardest to break CD is not as break resistant and unaltered polycarbonate sheet. I strongly discourage the use of CD's or DVD's for anything in Model rocketry except prehaps spool rockets as long as you don't mind replacing them after each flight.

You shouldn't accuse anyone of spreading false information without getting the facts straight yourself. It is rude. In this case your are the one with the false information.

CD's are in fact mostly pure polycarbonate, the polycarbonate is required for its optical properties (index of refraction) needed for CD operation. There is a tiny (mils) laminate on the printed side to allow the CD to accept printing, and tiny layers (~mil) of protective resin on the optical side.

The brittleness or toughness of CD has nothing to do whether it is polycarbonate or not, it has to do with the MW (molecular weight) of the polycarbonate used. Low MW tend to be hard but brittle, larger MW tends to be softer and tougher.

YMMV.

Here is reference to optical disc construction.
https://www.clir.org/pubs/reports/pub121/sec3.html

Also here is the material spec for the CD/DVD optical disc material with currently the largest market share.
https://www.ides.com/grades/ds/E102872.htm
Note the frequency of the words Lexan and High purity.

I'll anxious to see the references that support your post.

Micromeister said:

FYI:
Lets try to be careful not spreading false or misleading information please.
Not all CD's are alike, and NONE are "Pure Polycarbonate" they are all a laminated manufactured form of polycarbonate and other materials. Some are quite brittle and shatter when flexed while some can be tougher to break. However even the hardest to break CD is not as break resistant and unaltered polycarbonate sheet. I strongly discourage the use of CD's or DVD's for anything in Model rocketry except prehaps spool rockets as long as you don't mind replacing them after each flight.

Click to expand...

Delta-IV said:

Yes, I bought a scoring knive at Lowes and just a couple of passes I put the piece over an edge and easily snapped it with a very clean cut.

I have to disagree with "micro" at least here in Florida. I was able to buy a few sheets of real Lexan XL10 at Lowes.

For smaller rockets, the clear and much cheaper acrylic has worked fine and is even easier to cut.

Did you know that Lexan no longer is owned by GE? It was sold in 2007 to a Saudi owned company SABIC (Saudi Basic Industries Corporation).

Click to expand...

Delta You may be correct about your local stores in Fla. You guys to have to deal with those pesky Hurricanes down there.

lets me be Clear. Both HD and lowe's do not purchase for nationwide distrubution any Lexan or polycarbonate sheet or at least did not as of November of 2009. Your local Florida stores may be purchasing it locally for that market. But Please be careful when you buy. If you can not clearly read "GE Lexan" on the liner, don't believe for a second it's polycarbonate, it is also a SABIC product from Mexico formally AtoHass modified Acrylic with a blue semi-transluscent liner (NO lableing).

While it's true GE Polymershapes division was sold to the global HUGE conglomerate SABIC innovative plastics. Lexan is still made in the USA as well as 25 other countries now thur SABIC polymershapes. My point is don't be fooled into thinking your getting polycarbonate just because someone from the store tells you it's "Lexan".
Acrlyics and modified acrylics are not suitable for use on flying model rockets of any size. Both are simply to brittle to take flight and landing stress without damage even the smallest models. but this is way off subject we're looking for sources of Polycarbonate.

Just don't want you guys getting ripped off as I and many have been over the last few years
Delta is exactly correct about score/snapping. it also saws very well with 18T blades (band, sabre or scroll).

One more thing: If your looking for polycarbonate in thicknesses under .063" (1/16") you'll need to be looking for Polycarbonate film. sometimes with matte finish called Calendered Films. These can be had from .050" to .010" in smaller standard sheets 20" x 40" or 24" x 48" depending on thickness.

jderimig said:

You shouldn't accuse anyone of spreading false information without getting the facts straight yourself. It is rude. In this case your are the one with the false information.

CD's are in fact mostly pure polycarbonate, the polycarbonate is required for its optical properties (index of refraction) needed for CD operation. There is a tiny (mils) laminate on the printed side to allow the CD to accept printing, and tiny layers (~mil) of protective resin on the optical side.

The brittleness or toughness of CD has nothing to do whether it is polycarbonate or not, it has to do with the MW (molecular weight) of the polycarbonate used. Low MW tend to be hard but brittle, larger MW tends to be softer and tougher.

YMMV.

Here is reference to optical disc construction.
https://www.clir.org/pubs/reports/pub121/sec3.html

Also here is the material spec for the CD/DVD optical disc material with currently the largest market share.
https://www.ides.com/grades/ds/E102872.htm
Note the frequency of the words Lexan and High purity.

I'll anxious to see the references that support your post.

Click to expand...

"Mostly Pure" lets stop this. Something is either pure or its not.... CDs are NOT.
Fact is CD's and DVD's should not be used as fins on mod-rocs. They MAY Shatter on landing or in flight possibly causing unanticapated flight paths or falling debris. I will continue to post this each and every time you insist on suggesting this ill advised use.

Micromeister said:

"Mostly Pure" lets stop this. Something is either pure or its not.... CDs are NOT.
Fact is CD's and DVD's should not be used as fins on mod-rocs. They MAY Shatter on landing or in flight possibly causing unanticapated flight paths or falling debris. I will continue to post this each and every time you insist on suggesting this ill advised use.

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John,

Your post implied CD's were less or inferior polycarbonate than unspec'd polycarbonate sheets bought from various plastic suppliers. I simply wanted to correct that with references.

As far as strength failure concerns you have, that is currently opinion without any support in the form of data, unless you have first hand experience of the failures you imagine.

Admittedly I don't have any first hand experiences of success either. However I am unconvinced that CD high grade polycarbonate is any weaker than pig-in-a-poke polycarbonate sheet you buy off the street.

Lacking that users can decide for themselves. After all we are talking about small rockets with small loads. I recommend someone who is interested in possibly a very strong fin made from virtually free material to cut one fin out of a CD blank, one from the same thickness of balsa (a widespread used material) and one from aircraft ply (another widespread material). Compare the strengths by rough handing, bending, dropping etc and see for yourself what the strengths are. I will bet a dozen donuts that the CD blank will be shockingly superior to the other materials mentioned.

I would also like to move the "CD blank" versus "pig-in-a-poke polycarbonate sheet" issue settled by actually strength testing each material. We can take this discussion out of the opinion realm and into the fact regime.

I can contact Doc Drake to see what samples are needed and if he is willing to perform the evaluation. I can provide the CD material samples, can you provide the sheet samples?

jderimig said:

John,

Your post implied CD's were less or inferior polycarbonate than unspec'd polycarbonate sheets bought from various plastic suppliers. I simply wanted to correct that with references.

As far as strength failure concerns you have, that is currently opinion without any support in the form of data, unless you have first hand experience of the failures you imagine.

Admittedly I don't have any first hand experiences of success either. However I am unconvinced that CD high grade polycarbonate is any weaker than pig-in-a-poke polycarbonate sheet you buy off the street.

Lacking that users can decide for themselves. After all we are talking about small rockets with small loads. I recommend someone who is interested in possibly a very strong fin made from virtually free material to cut one fin out of a CD blank, one from the same thickness of balsa (a widespread used material) and one from aircraft ply (another widespread material). Compare the strengths by rough handing, bending, dropping etc and see for yourself what the strengths are. I will bet a dozen donuts that the CD blank will be shockingly superior to the other materials mentioned.

I would also like to move the "CD blank" versus "pig-in-a-poke polycarbonate sheet" issue settled by actually strength testing each material. We can take this discussion out of the opinion realm and into the fact regime.

I can contact Doc Drake to see what samples are needed and if he is willing to perform the evaluation. I can provide the CD material samples, can you provide the sheet samples?

Click to expand...

John:
Not sure why you feel your reference data has much direct bearing on what we are talking about. As it is the laminating process that changes the structure of the polycarbonate during the CD/DVD manufacturing process. Further Sheet Polycarbonate as provided to the Sign and Plastic industry particularly the S300 sign grade clear is a Pure form of Polycarbonate sheeting. Since I have extensive first hand experience with this material in both professional and personal use I feel quite qualified to speak with authority on its use.

If you have NO direct experience with the material why the heck are you typing? You've done nothing but muddy the waters with useless false mis-information.

I'm in the sign business, we use polycarbonates constantly. I am also an avid Odd-Roc builder and flyer with more the 20+years experience with use of this and MOST plastics and there attachment and/or adhesives. Further I have personally tested a wide aray of different CD and DVD's in break tests which have shown that these products are NOT easily identified as being brittle or not. One can not tell by look or feel weither a particular Dics will shatter or bend/break when folded. That fact alone makes it an unwise choice for fins, when KNOWN lagitamate S100 to S300 or any of the UV coated XL serier Polycarbonates are extremely Break resistant for our applications. Fact is any of the polycarbonate sheet products avaiable from ANY random "street source" can be cold formed over 90° without breaking.

One of my TEST beds was a two disc CD spool rocket build with two used High dollar CDS. On each and every fight the spool flew perfectly transistioned into the always KEWL backward spinning recovery and snapped the leading dics on impact every single flight....10 flights 10 breaks. A replacement spool using the same core tube was constructed used PLain OLD S300 clear Polycarbonate with flew about 8 flights until a C6-0 cato. which completely destroyed the BT-20 & 19mm cardboard motor tubing but both polycarbonate discs are perfectly fine and will be used on another spool. I have Many other Odd-Rocs, PMC and Scale models with Clear Polycarbonate fins (S300, S100 and XL10) that have been flying without a single brake or bend logging hundreds of flights of that 20+ years.

Your assumption is incorrect, CD/DVD's ARE FAR inferrior to any of the commerically available Lexan, Tuffak polycarbonate stock sheeting.
The rest of your post is completely useless, As strength testing has already been done with proven..REAL world results.
That said I'd be happy to send samples of Random "Pig-in-a-Poke Clear Polycarbonate sheeting for testing...I already know the outcome.

That's a sweet lookin' Vanguard, John (aka, Micromeister). What motors have you flown it with?

Greg

Micromeister said:

IF you have NO direct experince with the material why the heck are you typing? .....


..... The rest of your post is completely useless. As strength testing has already been done. with proven..REAL world results.

Click to expand...

Again another classy response.

I am not arguing CD blank is not the strongest form of polycarbonate sheet. I am arguing that may be strong enough for simple fin duty as compared to other commonly used materials for this purpose such as balsa, plywood, G10 at equivalent thickness.

Micromeister said:

Further I have personally tested a wide aray of different CD and DVD's in break tests which have shown that these products are NOT easily identified as being brittle or not.

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Fantanstic! I would be very interested in seeing your test procedure and results. What was the measured response? What strength parameter was measured? Yield strength? Ultimate strength? Elongation? Impact strength? What was the range of values you observed? How did these measured values compare to balsa? Aircraft ply? G10?

Generally, Lexan is chosen to create clear fins, so CDs wouldn't be a good substitute simply because they aren't clear.

The Lexan I've used will bend about 90 degrees without breaking. I don't think CDs will. I know I've easily broken some CD-Rs when I was disposing of them.

BTW ... I proved that Lexan will break:

https://www.payloadbay.com/video-7959.html



-- Roger

Note the Noone has said or implied the Lexan or Polycarbonate is Unbreakable, IT IS NOT. During cold weather or in temps at or below 32°f it will snap just like most other plastics.
If placed in a freezer or in temps below 0 for more then 15minutes a sharp blow will cause polycarbonates to shatter like glass.

CD/DVDs should NOT be used for fins on model rockets for the reasons we have already discussed.

Unidentified dics cannot be distinguished from dics that will shatter when flexed therefore they are an UNWISE choice for ANY fin application.

jadebox said:

The Lexan I've used will bend about 90 degrees without breaking. I don't think CDs will.


-- Roger

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Balsa, plywood and G10 will not bend even close to 90 degrees without breaking. All of which are proven fin materials.

I don't want to continue a war thread. MM is right, don't even try to use CD blanks as fins, unless you want to try it.

jderimig said:

Balsa, plywood and G10 will not bend even close to 90 degrees without breaking. All of which are proven fin materials.

Click to expand...

Yes, but those materials are not brittle. My point is that CDs are, at least in my experience, more brittle than Lexan.

Lexan's not very expensive, not too hard to obtain, not too hard to manage, and clear. For those reasons it's a good choice for clear fins on rockets.

The cons are that it's heavier than other materials, glue doesn't stick well to it, and it's easily scratched.

-- Roger

Ture Balsa, Plywood, basswood and G10 etc don't bend 90° but can be flexed without shattering, a Large majority of CD/DVD cannot.
That sir is the difference.

This is not a war thread John: Seriously not trying to be a wiseguy here, Your simply incorrect in your assumption which those of us who actually know are trying hard give you better info.
To that end I will again ask that you please not suggest people use CD/DVDs as fin materal. Purchase Polycarbonate sheeting from qualified sources will greatly increase the builders chances of finding proper high value, low maintenance fin material.

GregGleason said:

That's a sweet lookin' Vanguard, John (aka, Micromeister). What motors have you flown it with?

Greg

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Thanks Greg: it's a commemorative to my Dad who worked on the real TV-3 and TV-4, He built the grapefruit satellites and their mock-ups along with much of the first stage Plus at NRL.
13mm motors: Depends on the day, but A3-4T or A10-3Ts are the norm

For small pieces of Lexan try contacting a local plastic fabricator or sign shop. They usually have a bin of end cuts and other scraps that they sell by the pound or just give away.

Me? I remain a fan of CD fins.

Thanks for the info guys! The material at HD did have "Lexan" all over the backing paper, so it may be a local thing here in Philly as well. But anyway it was much to thick.