Help! Glueing Russian Plastic - UK Vintage Radio Repair and Restoration Discussion Forum

wireful3 · 12th Mar 2007, 11:13 am

I have a VEF Transistor Multi-band Radio with a broken fixing stud. I tried glueing it with Araldite but had no success. I suspect it is not one of the "most plastics " that Araldite claims to stick.
I have previously had success in fabricating studs and repairing cases that appear similar but I guess it is a thermal setting plastic that is not very common. I washed the surface with meths to degrease it so I doubt whether tthis is the problem.
Any hints would be appreciated.

Thanks in advance

paulsherwin · 12th Mar 2007, 11:51 am

Superglue?

Paul

howard · 12th Mar 2007, 11:57 am

Hello John,

I have a 1962 VEF Convair 1 which had a broken plastic chassis mounting and I surrounded it with Araldite and it held OK. If superglue doesn't hold either, try some polystyrene cement (don't spill any on the case !)

Howard

GJR 11L · 12th Mar 2007, 12:43 pm

Polystyrene cement makes sense to me, as it is a solvent cement and as such, used correctly, will actually fuse together the surfaces to be joined, so restoring much of the original structural integrity in the affected area.

Superglue will work on polystyrene if you first prime the areas to be bonded with a permanent marker, or pay over the odds for the "plastics" superglue, which comes with a "primer stick" (permanent marker without the pigment, but the glue's the same and any old [solvent-based] marker will work).

wireful3 · 12th Mar 2007, 1:06 pm

Thanks all for the suggestions.
I had not tried superglue but it seems a good start. The polystyrene cement also seems a good bet.
I will heed your warning Howard, it seems like the plastic used for models and with these, cement in the wrong place really causes problems.

batterymaker1 · 12th Mar 2007, 1:08 pm

Make sure the surfaces are roughened up and dull before you apply any epoxy. The cement needs something with a "tooth" to grab onto. A smooth surface is only asking for trouble.

Tom_I · 12th Mar 2007, 1:09 pm

Then there's the old trick with a lot of hard plastics of painting the broken surfaces with cellulose thinners, then holding them together until the joint sets. With luck this can produce virtually invisible repairs.

Remember to arrange plenty of ventilation, and keep well away from naked flames.

Tom

Dave Moll · 12th Mar 2007, 3:32 pm

Quote:

Originally Posted by GJR 11L

Superglue will work on polystyrene if you first prime the areas to be bonded with a permanent marker

Now, that is a useful little tip that I didn't know about. And I presume that any marker left visible afterwards (if it hasn't been trapped under the glue) can be removed with meths.

GJR 11L · 12th Mar 2007, 3:45 pm

I guess it could, but I only ever use the marker pen in locations that won't be visible, otherwise I would bring out the inkless "primer" version that came with the superglue but isn't any more than an excuse to ramp up the price!
Used in this way, one "Primer" stick can last through about five or six tubes of glue, possibly more but mine is on its sixth as it happens.

By the same logic, any length of felt stuffed into the body of a marker pen and loaded with suitable solvent would work too.

That said, the best results I've had repairing such polystyrene cabinets as those found on the Russian set being discussed here as well as Bush MB60s and TR82s were achieved, perhaps unsurprisingly, with polystyrene cement and the brush that comes in the bottle with it. Don't use the pasty variety that comes in tubes unless you want to get it all over the place apart from on the job!

wireful3 · 14th Mar 2007, 3:51 pm

Just to tie things up, all the suggestions have have been a great help. I have had success with a belt and braces approach combining several of the tips.

After degreasing with meths I used superglue to hold the broken piece in place. Then I applied some plastic weld from a model shop to the case and the broken piece as a primer. I built up a fillet of Araldite to make the secure fixing. Past experience has shown standard Araldite to be far superior to rapid, the superglue fixing meant there was no problem in keeping it stable for the longer setting time.

So far the joint seems to be very strong and taking all the loads I have put on it.

Thanks again to all.

12th Mar 2007, 11:13 am	#1
wireful3 Retired Dormant Member Join Date: Sep 2003 Location: Bristol, UK. Posts: 808	Help! Glueing Russian Plastic I have a VEF Transistor Multi-band Radio with a broken fixing stud. I tried glueing it with Araldite but had no success. I suspect it is not one of the "most plastics " that Araldite claims to stick. I have previously had success in fabricating studs and repairing cases that appear similar but I guess it is a thermal setting plastic that is not very common. I washed the surface with meths to degrease it so I doubt whether tthis is the problem. Any hints would be appreciated. Thanks in advance

12th Mar 2007, 11:51 am	#2
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,960	Re: Help! Glueing Russian Plastic Superglue? Paul

12th Mar 2007, 11:57 am	#3
howard Nonode Join Date: May 2005 Location: Godalming, Surrey, UK. Posts: 2,593	Re: Help! Glueing Russian Plastic Hello John, I have a 1962 VEF Convair 1 which had a broken plastic chassis mounting and I surrounded it with Araldite and it held OK. If superglue doesn't hold either, try some polystyrene cement (don't spill any on the case !) Howard

12th Mar 2007, 12:43 pm	#4
GJR 11L Heptode Join Date: May 2004 Location: Ellington, Northumberland, UK. Posts: 815	Re: Help! Glueing Russian Plastic Polystyrene cement makes sense to me, as it is a solvent cement and as such, used correctly, will actually fuse together the surfaces to be joined, so restoring much of the original structural integrity in the affected area. Superglue will work on polystyrene if you first prime the areas to be bonded with a permanent marker, or pay over the odds for the "plastics" superglue, which comes with a "primer stick" (permanent marker without the pigment, but the glue's the same and any old [solvent-based] marker will work). __________________ John.

12th Mar 2007, 1:06 pm	#5
wireful3 Retired Dormant Member Join Date: Sep 2003 Location: Bristol, UK. Posts: 808	Re: Help! Glueing Russian Plastic Thanks all for the suggestions. I had not tried superglue but it seems a good start. The polystyrene cement also seems a good bet. I will heed your warning Howard, it seems like the plastic used for models and with these, cement in the wrong place really causes problems.

12th Mar 2007, 1:08 pm	#6
batterymaker1 Heptode Join Date: Apr 2006 Location: Indianapolis, Indiana, USA. Posts: 674	Re: Help! Glueing Russian Plastic Make sure the surfaces are roughened up and dull before you apply any epoxy. The cement needs something with a "tooth" to grab onto. A smooth surface is only asking for trouble. __________________ Just playing with high voltage....

12th Mar 2007, 1:09 pm	#7
Tom_I Heptode Join Date: Jul 2006 Location: North Herts. UK. Posts: 549	Re: Help! Glueing Russian Plastic Then there's the old trick with a lot of hard plastics of painting the broken surfaces with cellulose thinners, then holding them together until the joint sets. With luck this can produce virtually invisible repairs. Remember to arrange plenty of ventilation, and keep well away from naked flames. Tom

12th Mar 2007, 3:45 pm	#9
GJR 11L Heptode Join Date: May 2004 Location: Ellington, Northumberland, UK. Posts: 815	Re: Help! Glueing Russian Plastic I guess it could, but I only ever use the marker pen in locations that won't be visible, otherwise I would bring out the inkless "primer" version that came with the superglue but isn't any more than an excuse to ramp up the price! Used in this way, one "Primer" stick can last through about five or six tubes of glue, possibly more but mine is on its sixth as it happens. By the same logic, any length of felt stuffed into the body of a marker pen and loaded with suitable solvent would work too. That said, the best results I've had repairing such polystyrene cabinets as those found on the Russian set being discussed here as well as Bush MB60s and TR82s were achieved, perhaps unsurprisingly, with polystyrene cement and the brush that comes in the bottle with it. Don't use the pasty variety that comes in tubes unless you want to get it all over the place apart from on the job! __________________ John.

14th Mar 2007, 3:51 pm	#10
wireful3 Retired Dormant Member Join Date: Sep 2003 Location: Bristol, UK. Posts: 808	Re: Help! Glueing Russian Plastic Just to tie things up, all the suggestions have have been a great help. I have had success with a belt and braces approach combining several of the tips. After degreasing with meths I used superglue to hold the broken piece in place. Then I applied some plastic weld from a model shop to the case and the broken piece as a primer. I built up a fillet of Araldite to make the secure fixing. Past experience has shown standard Araldite to be far superior to rapid, the superglue fixing meant there was no problem in keeping it stable for the longer setting time. So far the joint seems to be very strong and taking all the loads I have put on it. Thanks again to all.