# Gluing plastics?



## Faust (Apr 5, 2011)

I work in a plastics plant where I extrude and thermoform plastic sheet. The other night it was a slow night at work so I went and cut me some pieces of scrap sheet with the idea of possibly using them as spacer material in a laminated slingshot. Now the problem is that just about every type of epoxy or other glue I've looked at says it's not recommended for use with Polyethylene or Polypropylene. So does anyone know of a method for bonding layers of Polypropylene sheet that would hold up to use as a slingshot. I have black , blue and white sheet and planned on layering them to make a nice middle spacer layer and then pinning the entire finished product.


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## bbshooter (Jun 3, 2010)

A possible place to start looking for information...

From the U. S. Plastic Corp website a short how to do it article on glueing...

http://www.usplastic.com/knowledgebase/article.aspx?contentkey=584

And also from U. S. Plastic, glues they sell...

http://www.usplastic.com/catalog/search.aspx?search=Acrylic%20Adhesive%20SC-125&page=1


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## e~shot (Jun 3, 2010)

use Chloroform cheap and easy


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## Charles (Aug 26, 2010)

Another possibility is to use a "mechanical" technique. Rough cut two pieces of wood and one of plastic ... make pieces just a bit larger than the final form. Rough sand the plastic. Basically, just drill lots of small holes all the way through the plastic in various unobtrusive places. Apply epoxy to one layer of wood, then place the drilled plastic on top. Apply more epoxy on the top of the plastic to fill in the holes you have drilled and cover the plastic well. Then put down the second layer of wood. Clamp, wipe off excess and let cure. After it is cured, you can then do your final cut and finish. Even if the epoxy does not bond super well to the roughed plastic, the holes filled with epoxy will act as internal rivets, and should hold everything quite firmly. I think someone on this forum has used something like this technique already.

Cheers ....... Charles


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## Faust (Apr 5, 2011)

Thanks for that idea Charles. I had already though about using pins through the piece to help hold it together but i like this internal riveting idea.After posting this i did a bit of searching and actually did find a glue made by 3m that works on Polypropylene, unfortunately it cost over $30 a tube and then requires a special applicator gun that costs another $50. Some of the sheet i have is laminated with a clear film on one side that is put there so that it can have other film heat bonded to it. The laminated side may be able to be glues but it's only on one side. And I was also toying with the idea of using the green cutting board material i have as the outer layers and then this other plastic as the middle layer, making a fully plastic laminated slingshot. If it comes down to it i may just pin and bolt all the layers together.


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## ZDP-189 (Mar 14, 2010)

All plastics have different properties. Mechanical fixings usually work well, sometimes, contact adhesive, sometimes chloroform. Other plastics can be heat welded. In your case, try 3M Scotch Weld.


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## Charles (Aug 26, 2010)

For other applications (making fine art etchings) I have used acetone based contact cement to adhere thin aluminum sheet to plexiglass. Under high heat conditions, such bonds will warp and loosen ... different expansion coeeficients for plexi and aluminum, and contact cement softens under high heat. As long as the heat is not too great, it seems to hold pretty well. I have made a lot of inexpensive etching plates this way. But when printing etchings, all the pressure of the press is holding the layers together ... not the same as on a slingshot. Might be worth experimenting ... but personally I do not regard the bond as being strong enough on a slingshot for me to put a lot of work into it.

Cheers ....... Charles


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## ZDP-189 (Mar 14, 2010)

If you use an adhesive with PP/PET, I suggest heavy keying. As a knifemaker, I'd not use it on a handle except in desperation and then I'd combine adhesives with a mechanical fixing. Slingshots require even better bonding as they may bend and delaminate. Can you use a single solid piece? Can you do a pressure and heat weld?


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## Faust (Apr 5, 2011)

ZDP-189 said:


> All plastics have different properties. Mechanical fixings usually work well, sometimes, contact adhesive, sometimes chloroform. Other plastics can be heat welded. In your case, try 3M Scotch Weld.


Had not heard of using chloroform before I posted on here so may give that a try. At work the only lamination we do with the stuff is done as the material is initially extruded. And well it's not really an option to use that machine for something like this since it looks pretty much like the one on this companies main page http://www.ptiextruders.com/en/default.aspx and I doubt my boss wouldn't like me trying to laminate different colors together









The only other materials I've heard will work is the 3M Scotch Weld DP-8005. The only problem is that the cost is pretty prohibitive for me since the tube of glue is like $36 and the applicator gun is $89 and the special plunger needed for is another $12.

The only other thing I've seen at work that will stick it together is basic spray adhesive but it is't a permanent bond it just holds it in place till you peel it up.


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## ZDP-189 (Mar 14, 2010)

Chloroform works on acetate (perspex). I have not tried it on other plastics.


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## Faust (Apr 5, 2011)

ZDP-189 said:


> If you use an adhesive with PP/PET, I suggest heavy keying. As a knifemaker, I'd not use it on a handle except in desperation and then I'd combine adhesives with a mechanical fixing. Slingshots require even better bonding as they may bend and delaminate. Can you use a single solid piece? Can you do a pressure and heat weld?


The sheet I'm dealing with is only .03 to .045 thick usually, some pieces as thin as .012 so it's pretty hard to heat bond layers together without it completely melting out and loosing shape.


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## Ry-shot (Jul 22, 2011)

sand the plastic to give something for the wood to grip on-to .


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## e~shot (Jun 3, 2010)

ZDP-189 said:


> Chloroform works on acetate (perspex). I have not tried it on other plastics.


Yes. Dan, I mean for perspex.


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## Hrawk (Oct 25, 2010)

Chloroform is best, but if you cannot get it, than the best product is Acri-Bond 105

http://www.acrylictech.com.au/Acri-Bond-105.html


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## alfshooter (May 11, 2011)

My experience with the plastic has been simple, I've joined the pieces with Loctite and inlays, the resistance is very good.


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## ZDP-189 (Mar 14, 2010)

Having spoken to several people in the trade, I advise that this isn't a good idea. Sorry.


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## alfshooter (May 11, 2011)

ZDP-189 said:


> Having spoken to several people in the trade, I advise that this isn't a good idea. Sorry.


Hola a todos
Me llamo Alfredo y tengo 48 años , llevo practicando y haciendo tirachinas mas de 35 años , soy uno de los promotores de torneos de tiro , mas antiguo de España , no sé, cuantos tirachinas abre hecho , pero le aseguro que muchos .
Varios tirachinas que ve usted en la foto han ganado torneos , por lo que compruebo en su comentario , no deve haber probado este sistema tan simple ,economico y resistente , yo simplemente he aportado una informacion coerente y por supuesto eficaz .
¿usted cree que si esto no fuera bueno lo publicaria ?
¿ que intereses tiene usted?
Es la segunda vez que me hace un comentario desagradable ,¿ tiene algun problema comigo? , ¿que es para usted inteligible?.
Veo que usted es un Moderator , usted deveria tener mas diplomacia.
Saludos


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## Rapier (May 28, 2011)

Like Charles first said. Drill lots of Lil holes and make sure epoxy goes all the way through to each piece of timber. This might be problematic with really thin sheets though. I've had to use steel pins all the way through everything


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## ZDP-189 (Mar 14, 2010)

alfshooter said:


> Having spoken to several people in the trade, I advise that this isn't a good idea. Sorry.


Hola a todos
Me llamo Alfredo y tengo 48 años , llevo practicando y haciendo tirachinas mas de 35 años , soy uno de los promotores de torneos de tiro , mas antiguo de España , no sé, cuantos tirachinas abre hecho , pero le aseguro que muchos .
Varios tirachinas que ve usted en la foto han ganado torneos , por lo que compruebo en su comentario , no deve haber probado este sistema tan simple ,economico y resistente , yo simplemente he aportado una informacion coerente y por supuesto eficaz .
¿usted cree que si esto no fuera bueno lo publicaria ?
¿ que intereses tiene usted?
Es la segunda vez que me hace un comentario desagradable ,¿ tiene algun problema comigo? , ¿que es para usted inteligible?.
Veo que usted es un Moderator , usted deveria tener mas diplomacia.
Saludos

_Hi all
My name is Alfredo and I am 48 old, I've been practicing and slingshot by more than 35 years, I am one of the promoters of shooting tournaments, oldest in Spain, I do not know how many catapults opens fact, but I assure you many.
Several catapults you see in the picture have won tournaments, so I check in his commentary, deve not have tried this system so simple, inexpensive and durable, I have simply made a coerente information and of course effective.
Do you think that if this is not good to publish it?
What interests do you have?
It is the second time I made a comment unpleasant Comigo Any problems? , What is it for you intelligible.
I see you're a Moderator, you have more diplomacy Deveria.
regards_
[/quote]

* above translation by translate.google.com

I'm not sure I understand entirely. If you have slingshots to show or ideas to post, please do.

If you are referring to my comment above, allow me to clarify:

The topic's original poster, Faust, was asking for advice regarding the gluing of multiple layers of thin sheets of polyethylene (PE) or polypropylene (PP) plastic into a laminate billet. I have some experience in working with plastics and some contacts in the plastics industry and am trying to help. I previously advised that I had been told by one contact in the plastics trade that PE and PP could be adhered together using a special adhesive. I went back and explained Faust's plan to lay up a billet that would be cut into a Y-shaped fork and then subject to side load at the tips. I was told that this was inadvisable as these plastics are not only hard to bond to, but are also flexible. This means that the billet is likely to delaminate sooner or later. I wish to save Faust from wasting his time trying to make it work. A better approach would be to use a solid cast billet. PE and PP offcuts are so inexpensive that it would be cheaper to start with a solid sheet than to purchase the glue necessary to lay up the laminate.

If this explanation is not clear enough, or we are at crossed purposes, please let me know.


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## alfshooter (May 11, 2011)

Friend Ok


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## ZDP-189 (Mar 14, 2010)

alfshooter said:


> Friend Ok


I'm glad we have an understanding. Until I checked a minute ago I wasn't aware that you had previously posted in this topic. I had not seen your post and wasn't commenting on your slingshots, but replying to Faust. Your slingshots appear to be solid plastic sheet with wood facings and are not what I was talking about. I can't comment about whether that should work well or not, I suppose it depends on the rigidity and thickness of the plastic.


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## alfshooter (May 11, 2011)

ZDP-189 said:


> Friend Ok


I'm glad we have an understanding. Until I checked a minute ago I wasn't aware that you had previously posted in this topic. I had not seen your post and wasn't commenting on your slingshots, but replying to Faust. Your slingshots appear to be solid plastic sheet with wood facings and are not what I was talking about. I can't comment about whether that should work well or not, I suppose it depends on the rigidity and thickness of the plastic.
[/quote]

Hello ZPD-189
My respects, have had a misunderstanding.
The use of the translator is complicated.


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