voice coil to aluminium/kapton adhesive - diyAudio
Go Back   Home > Forums > Loudspeakers > Multi-Way

Multi-Way Conventional loudspeakers with crossovers

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 11th November 2011, 11:59 AM   #1
jayadev is offline jayadev  India
diyAudio Member
 
jayadev's Avatar
 
Join Date: May 2006
Location: Kerala
Default voice coil to aluminium/kapton adhesive

I have planned to wind coil former for my home subwoofer 15 inch two of them (and yes I got many more .
BTW,I am not a noob in this and had resurrected many of loudspeakers before.


so far one thing which troubled me was the right adhesive for the coils.

I have wound formers on aluminium sheets and kapton former. and you wont believe what I used as glue was "Araldite" yeah the epoxy, same mixing and pasting thingie.

as you may have realized, anomalies were bit too serious, araldite is just common purpose glue ,not at all hifi.
it is too viscous adding undesirable weight to former.

I wish to know if there is anything available like "henron voice bonder" or similar thing which I can buy online for small quantity.I realized henron no longer supplies this kind of adhesives anymore.


Please advice.
  Reply With Quote
Old 11th November 2011, 06:15 PM   #2
diyAudio Member
 
Join Date: Nov 2003
Location: California
All the coil winding I did used adhesive pre-coated on the wire. For example, see this link: MWS Wire Industries - Bondable Magnet Wire

You can probably make many different types of glue work as long as they give you the strength you need at the upper temperature limit you are working at and are easy to apply in the right quantities.
  Reply With Quote
Old 11th November 2011, 06:43 PM   #3
jayadev is offline jayadev  India
diyAudio Member
 
jayadev's Avatar
 
Join Date: May 2006
Location: Kerala
Thanks John.

As you said it temperature and strength, yes I believe if manufacturer have such a glue specifically for voice coil winding I can use it with closed eyes.

Right now I am experimenting and they have all failed.some are too brittle some remain soft, rubbery some changed their character after short term use.
so it has become deemed necessary to find out right kind of adhesive for proer result.

The pre-coated wire you mentioned I am dead sure It is not available in my country and the one shown in website do they ship internationally in small quantity?

I believe solvent bonding should be the appropriate one for my purpose.
  Reply With Quote
Old 11th November 2011, 07:07 PM   #4
diyAudio Member
 
Join Date: Nov 2003
Location: California
No idea on shipping internationally. I doubt you'd want to pay for that, and I doubt they sell in small quantities. You might try researching the types of glues they mention to try to find something suitable for diy use.
  Reply With Quote
Old 12th November 2011, 02:46 PM   #5
JMFahey is offline JMFahey  Argentina
diyAudio Member
 
JMFahey's Avatar
 
Join Date: Mar 2009
Location: Buenos Aires - Argentina
Epoxy,*is* the standard voice coil wire adhesive, but there are many types and viscosities.
Araldite makes hundreds of different types, you need one which is somewhat thicker than honey; no more, no less.
It also hardens in *hours* at ambient temperature (up to 8 to 16 hours ar 20ºC), only way of speeding that is placing it in an oven (up to 100ºC which cuts curing time to less than an hour; any more and it bubbles); absolutely forget "10 minute" cr*p.
I don´t remember by heart *which* Araldit I used but its viscosity was as I just said, and it was mixed in a 2:1 ratio, maybe that´s enough for you to find it in their huge catalog.
The one I´m using now *is* Araldit made (or so the seller claims) but he buys it in 200Kg drums and reloads (and relabels) 250g and 1Kg cans so the brand and type is local, not much use to you.
You must slightly heat the die around which you wind it, for it to become slightly more liquid and "wet" the surfaces better.
Apply a little too much and then wipe the excess.
It hardens very rigid , yet heat and impact resistant.
You must use anodized aluminum or slightly scratch its surface with #600 emery paper or it won´t adhere to aluminum´s oxide "glass" surface.
Same with Kapton.
Good luck.
PS: I have been making my own voice coils for almost 40 years now.
  Reply With Quote
Old 22nd May 2012, 06:20 PM   #6
jayadev is offline jayadev  India
diyAudio Member
 
jayadev's Avatar
 
Join Date: May 2006
Location: Kerala
Thank you JMFahey .
I missed this thread completely sorry for that .I have tried with epoxies and they havent let me down yet , but I feel there is something more exotic and specific so search is still on.
  Reply With Quote
Old 22nd May 2012, 07:26 PM   #7
godfrey is offline godfrey  South Africa
diyAudio Member
 
Join Date: Nov 2009
Location: Cape Town
What about the stuff used to patch holes in car exhaust systems e.g. Gun Gum. That should withstand the heat and vibration.
  Reply With Quote
Old 22nd May 2012, 11:08 PM   #8
VaNarn is offline VaNarn  Australia
diyAudio Member
 
Join Date: Dec 2010
Location: Ivanhoe
jayadev,having been in the same situation many times,I have found it necessary to speed up the drying process when using 'Araldite(marketed in Australia by Selleys) as the bonding material.By doing this,the moisture contamination is reduced and the mixture thins, allowing any excess to be wiped away.A simple method of doing this procedure is by way of using a variable dc power supply connected to the freshly wound voice coil and allowing the current flow to bring the curing temperature to a suitable level.With aluminium formers it does pay to rub down the surfaces with a fine grade of wet and dry paper to remove any protective coating that may have been applied. I am not fond of the wetted wire technique as I have come across too many failures in the past,especially the blue coated variety and the tendency for the winding to seperate under moderate heat.Also the coil rigidity is improved with epoxy and the heat treatment.
  Reply With Quote
Old 22nd May 2012, 11:17 PM   #9
jayadev is offline jayadev  India
diyAudio Member
 
jayadev's Avatar
 
Join Date: May 2006
Location: Kerala
Vanarn, I get you.
But what my concern is the undesirable weight of epoxy adhesive and of course quick dry is major advantage.
I have stripped many voice coils to figure out what they might be using but all the time I am left with despair. My observation is manufacturers, use very low viscosity adhesives which spread out evenly and they withstand high temperature with very good bonding strength.
Araldites which I have used so far is as thick as honey and when dry they are very far from uniform over the winding- I hate to see that!!



I am sure there are experts laughing at me in this forum. I am not manufacturer or high end expert but an audio enthusiast...this is the only way I got!!
  Reply With Quote
Old 23rd May 2012, 01:36 AM   #10
VaNarn is offline VaNarn  Australia
diyAudio Member
 
Join Date: Dec 2010
Location: Ivanhoe
The answer for your winding method is to control the tension of the wire that allows it to displace the 'Araldite" at room temperature. A more liquid adhesive that spreads everywhere is not helpful.To repeat myself,heating a freshly wound coil,before curing takes place,results in the situation where the honey-like viscosity changes to a watery composition,which allows for the surplus to be wiped away and this ensures that the unwanted mass is kept to a minimum.If you achieve the correct methodology you will end up with a voice coil replacement that is better than what most manufacturers use especially if you add a reinforcement sleeve to the v.c.former neck and carefully bond the the assembly to the cone apex.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Glue for aluminium to kapton Rob Dingen Planars & Exotics 5 19th November 2011 03:15 AM
Voice Coil TheReaper Subwoofers 4 27th October 2011 06:11 PM
voice coil rubbing? Dr.H Multi-Way 2 29th January 2009 02:57 PM
Voice Coil Formers... Kapton vs Nomex vs Aluminum vs GF/TIL OlogyAudio Multi-Way 3 1st June 2007 03:27 AM
Single Voice Coil Vs Double Voice Coil Subwoofer Workhorse Car Audio 6 12th April 2007 07:36 AM


New To Site? Need Help?

All times are GMT. The time now is 06:40 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2