# joining phenolic plastic



## chippy1970 (25 Sep 2010)

i'm in the middle of making a router table and have a few offcuts of 12mm thick phenolic plastic that I might make the fence out of. Does anyone have any tips for fixing it together. i'm thinking of screwing in the edge of the plastic with either self tappers or maybe tapping it and using machine screws. I suppose if I use glue epoxy would be best ? 

Anyone who's done any of the above please let me know how you got on. 

Chris


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## cgw59 (25 Sep 2010)

Hi,
i work in the technology dept of a local High school, we use quite a lot of acrylics and the best adhesive for these or plastics is a substance called Tensol. If you know any one in a school they may be able to get you some as it would be expensive to buy a tin for just one job.


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## chippy1970 (26 Sep 2010)

I tested out a sample today and found you can tap a thread in the edge very well. So I went ahead and joined two lengths together to make a 90 degree angle to make a start on my fence it worked very well. I might also use some glue on all joints when I finally screw it all together.

When I get a chance I will post some pics of the table, here below is a pic taken from a website showing another Phenolic fence with sliding faces similar to how mine will be.







Heres the site its from

http://www.ablett.jp/workshop/router_table.htm


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## Lons (2 Nov 2010)

Hey Chippy

Just seen the thread. You've already done the hard bit as engineering plastics such as "tufnol", machine very well and as you've found, take a threaded joint.

The advice to use "tensol" whils being well intended is incorrect though. Tensol is (or was) sold through ICI as a glue specifically formulated for "cast" acrylic. Their brand "perspex" in particular.

The best glue for phenolic engineering plastics is an epoxy resin such as one of the 2 part araldite 200 range. You would also get a strong, semi-flexible joint using a pu adhesive sealant such as sikaflex, duraflex, webbfix etc. screwfix and toolstation both sell similar stuff.

Do a web search and you'll find out the best ones though std araldite will work ok.

BTW, I used to sell and distribute all the main brands and though it was 20 years ago, the meterial properties don't change.

cheers

Bob


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## Eric The Viking (3 Nov 2010)

Lons":lww34ce5 said:


> The advice to use "tensol" whils being well intended is incorrect though. Tensol is (or was) sold through ICI as a glue specifically formulated for "cast" acrylic. Their brand "perspex" in particular.



Hi Bob,

Not to hijack a thread, but do you know a supplier of Tensol who will sell small quantities? I've a crack in my bike windscreen I want to deal with (not in a crucial area), and haven't found a source so far, at least locally. I'm guessing it's too inflammable to post.

Am I right in thinking it's Perspex dissolved in chloroform, and that it has a limited shelf life?

Cheers,

E.


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## Digit (3 Nov 2010)

Chloroform, not the medicinal quality, was much used for welding 'Perspex' years ago. It was replaced with 'Tensol Cement'.
Whether you could still obtain Choloroform I somewhat doubt, Tensol Cement is horrible enough!

Roy.


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## chippy1970 (4 Nov 2010)

In the end I didnt glue the parts together they didnt seem to need it after it was tapped and machine screwed together. Just recieved my small offcut of 6mm polycarbonate off ebay this morning so need to make the cover for the back of the fence next where the vac hose goes.


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## Lons (9 Nov 2010)

Eric The Viking":3spiac4n said:


> Lons":3spiac4n said:
> 
> 
> > The advice to use "tensol" whils being well intended is incorrect though. Tensol is (or was) sold through ICI as a glue specifically formulated for "cast" acrylic. Their brand "perspex" in particular.
> ...



Hi Eric

Just seen your post - sorry #-o 

To answer your questions:-
From memory, it's pretty much cast acrylic / chloroform.
ICI would never divulge the formula but it was a methylmethacrylate mixture. Packed in 500ml tins when I sold it.

Does have a shelf life but I've had some Tensol 12 for many years and still seems to work very well.

GPO probably wouldn't like it posted but if you're stuck, I can try to send you a small amount from my stock.

Amari sell it and have a branch in Bristol: Amari Plastics BristolUnit 1, St. Philips CentralAlbert RoadSt. PhilipsBristolBS2 OXJT: 0117 972 3900 0117 972 3900F: 0117 977 2722E: [email protected]

Williaam Cox Plastics used to sell it:- Bristol branch - 10 Liberty Ind. Park, Ashton Vale BS3 2SU tel: 0117 963 5000 - 0117 963 5000 fax: 0117 963 6123

Also look for point of sale suppliers / manufacturers eg leaflet and menu holders etc. who might give or sell you a small quantity.

Can get advice and information direct from ICI:- http://www.perspex.co.uk/

Hope that helps

Cheers

Bob


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## Eric The Viking (10 Nov 2010)

Lons":2ht9w7c7 said:


> From memory, it's pretty much cast acrylic / chloroform.
> ICI would never divulge the formula but it was a methylmethacrylate mixture. Packed in 500ml tins when I sold it.
> 
> Does have a shelf life but I've had some Tensol 12 for many years and still seems to work very well.
> ...



It certainly does!

The most urgent thing I need to fix is the bike windscreen, but I've also got a turntable cover to do (yes, I'm that old!) and some other bits too. 

One of our timber suppliers is in Ashton Vale, and I know Albert Road too, so I"ll follow those contacts up. The last time I had anything to do with Perspex construction it was having display covers made for electronics. The modelmakers who did it used UV-curing adhesive, which needs complex and expensive kit to work (although the results look brilliant). This ought to be a good DIY alternative.

Many thanks for the help.

E.


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## Lons (10 Nov 2010)

Eric The Viking":3ghitc5g said:


> It certainly does!
> 
> The most urgent thing I need to fix is the bike windscreen, but I've also got a turntable cover to do (yes, I'm that old!) and some other bits too.
> 
> ...



Erm - me too - my turntable is in the loft though (just in case?)  

When I started in the plastics distribution business many years ago, they were using neat chloroform applied with a glass syringe and hypo needle to join perspex (maybe that's where the phrase "sleeping on the job" came from :lol: ) - and a flame to polish edges.

Both worked very well but can you imagine the H&S guys response to that today. :shock: 

I've used both methods and wouldn't hesitate for my own use, observing obvious precautions of course.

cheers

Bob

PS I don't suppose you or anyone from your neck of the woods is going to Harrogate show? - I'm almost certainly going and could have dropped some off.


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## Digit (10 Nov 2010)

Yep! Where I served my apprenticeship they produced the BP petrol station signs and the raised part was placed in a sheet of phenolic with a matching groove in it which was filled with Chloroform. On a warm day it was great fun! 

Roy.


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## Eric The Viking (10 Nov 2010)

Lons":29f3tyfs said:


> My offer's there if you need it though
> 
> cheers
> 
> ...



It's a very kind thought, but I'm stuck here for the time being. I've promised the DC a functional guest bathroom by Christmas, and other work is somewhat backed-up too.

I'll try the folks in Ashton Vale next time I'm down there.

E.


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## Shrubby (11 Nov 2010)

Eric
For small quantities try EMA Plastic Weld - a good model shop should stock this.
It's dichloromethane and will bond acrylic(perspex) ABS etc
Matt


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## Lons (11 Nov 2010)

Digit":3tyonqa2 said:


> Yep! Where I served my apprenticeship they produced the BP petrol station signs and the raised part was placed in a sheet of phenolic with a matching groove in it which was filled with Chloroform. On a warm day it was great fun!
> 
> Roy.



:lol: :lol: :lol: happy days :wink:

Flame gunning the edges was the best fun though - smell was horrible but got great satisfaction watching the acrylic melt and turn into slightly wavy but glass clear edge. best of all were the flourescent perspex colours.

I wasn't directly involved with fabrication at work as I was a branch manager for a major distributor but experimented at home with the many offcuts I had access to. mostly from signmakers.

Built a simple line-bender as well and the whole family wanted those folded clear photo stands :duno: :? 

Bob


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## Digit (11 Nov 2010)

> Built a simple line-bender as well and the whole family wanted those folded clear photo stands



I am not required to incriminate myself! :lol: 

Roy.


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## chippy1970 (12 Nov 2010)

Digit":mf8ppr2v said:


> > Built a simple line-bender as well and the whole family wanted those folded clear photo stands
> 
> 
> 
> ...



Any easy way to bend 6mm lexan without a line bender ? heatgun maybe ?


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## Eric The Viking (12 Nov 2010)

chippy1970":11o2asgl said:


> Digit":11o2asgl said:
> 
> 
> > > Built a simple line-bender as well and the whole family wanted those folded clear photo stands
> ...



That's how I've done it, but you have to watch out for bubbles!


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## Digit (12 Nov 2010)

6 mill might be a bit of a problem chippy, depending on the length of the bend if using a heat gun.
As with any material the thicker it is the larger the radius of the bend will need to be.
On thinner material I have used two pieces of ply spaced evenly either side of the line then applied a heat gun.
It helps if the ply is clamped and the one side weighted down or clamped to some thing solid.
If the side is so clamped and the ply and clamps on the opposite side are heavy enough the plastic will bend under the weight as the correct temperature is reached.

Roy.


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## chippy1970 (13 Nov 2010)

I did it yesterday no problem at all apart from a load of bubbles right on the bend  doesn't matter though it came out fine will show it when I post an update on my router table build. I think I must have just warmed it up too fast I did take time on the lowest setting but maybe I should have taken a bit more time. 

I clamped it to a 4x2 cls that has slightly rounded edges to help with the bend then I shielded the rest of the lexan with some mdf leaving just a 6 mm strip on the bend line showing. That way only the bend line had direct heat.


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## Digit (13 Nov 2010)

That's the way chippy, it does sound as though you got the gun a bit too close. But practise makes perfect of course.
Marks/bubbles etc can be polished out with wet and dry and metal polish BTW.

Roy.


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## Lons (13 Nov 2010)

Bubbles mean it's been overheated. Not too much of a problem in most circumstances but - the poly will be much weakened and degraded at the bend and if that is important then better to use another method.

The easiest way to make an efficient linebender is to obtain a straight element from an old electric fire. A glass type is best.

Get some heat resistant material, as asbestos sheet is not now advisable, a usable alternative is flat verge support from a builders merchant fixed to support timbers each side of the element et voila!

loads of info on the net if searched.

cheers

Bob


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## chippy1970 (14 Nov 2010)

Digit":2gi9b6dy said:


> That's the way chippy, it does sound as though you got the gun a bit too close. But practise makes perfect of course.
> Marks/bubbles etc can be polished out with wet and dry and metal polish BTW.
> 
> Roy.



Yep thats exactly what I thought, its still functional and doesnt look too bad either  Im not worried about weakness as its not under any stress its only there to avoid fingers and cutter meeting and im quiet protective of my fingers at the moment :lol:


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