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General control line discussion => Open Forum => Topic started by: Motorman on June 15, 2014, 09:21:25 AM

Title: Glue for Aluminum
Post by: Motorman on June 15, 2014, 09:21:25 AM
What glue would you use to bond balsa to aluminum?


Thanks,
MM
Title: Re: Glue for Aluminum
Post by: Monty Summach on June 15, 2014, 09:40:03 AM
JB Weld works well on aluminum. Clean it well and buff with Scotchbrite or something similar.
Regards,
Title: Re: Glue for Aluminum
Post by: John Leidle on June 15, 2014, 10:22:59 AM
  Hysol Epoxy is another unbeatable adhesive ,I think its made by Weldwood but if you Google it you will find it I think Areo Spruse or what ever that place in So Cal is called sells it online at grossly inflated prices.
   John
Title: Re: Glue for Aluminum
Post by: Randy Cuberly on June 15, 2014, 02:18:13 PM
I think JB Weld works about as well as anything readily available for our purposes in modeling. 
In reality bonding aluminum to aluminum or to just about anything else is a little sketchy for any purposes if it's intended to be used in any kind of high stress application.
Tensile tests run on bonds with non-anodized aluminum show serious deterioration of the bond after a few months.
Aluminum is fortunately and unfortunately an active metal surface and is constantly changing unless it is made inactive by anodizing or a few proprietary coatings.  Paint, epoxy etc, will eventually form a layer of oxidation between the aluminum and the bonding material and become very weak.
Anodizing, of course gives an inactive surface to bond to and increases bonding strength by several factors and allows the bond to last as long as the bonding material itself will last.

For low strength applications like most modeling situations JB weld works fine.  If you have a magic supplier then 3M 2216 is the preferred epoxy for bonding aluminum (anodized aluminum).  It's also very, very expensive, with a short shelf life.

I know that's all more than anyone wanted to know about it but the whole truth is always a good thing!

Randy Cuberly
Title: Re: Glue for Aluminum
Post by: John Stiles on June 15, 2014, 02:50:35 PM
JB WELD is my choice...if it's possible, some small holes in the aluminum will guarantee a good grip. H^^
Title: Re: Glue for Aluminum
Post by: Jason Greer on June 15, 2014, 08:46:30 PM
I used to use 3M DP 460 epoxy to glue aluminum to carbon fiber in free flight construction. It has very high peel and shear strength. I never had a joint fail. This was 10 years ago, so there are probably better products now.
Title: Re: Glue for Aluminum
Post by: 55chevr on June 16, 2014, 05:30:55 AM
Motorcycle racers have used JB Weld on damaged engine cases with good results.  Works better than you would think
Title: Re: Glue for Aluminum
Post by: FLOYD CARTER on June 16, 2014, 10:48:22 AM
My old Toyota has been running the past 10 years with the radiator fixed with JB Weld.  but I think the base metal is brass, or something.

Floyd
Title: Re: Glue for Aluminum
Post by: Lauri Malila on June 16, 2014, 12:21:22 PM
With good surface preparation you can use allmost any glue as the weaker part of joint is allways the balsa.
There is all kinds of fancy stuff available, like etching products for making making adhesion to aluminium better, special glues and special anodizing (with chromium acid instead of the usual sulphuric). But is it really worth it with these toy airplanes?
My recommendation would be to roughen the aluminium well with #120...240 and to use just standard slow epoxy, perhaps with slightly more hardener to leave the glue slightly flexible.
One improvement would be to spread the glue before roughening and use it as cutting fluid. That way the fresh aluminium surface won't get in touch with air. Oxide layer is one big factor in bad adhesion.

L
Title: Re: Glue for Aluminum
Post by: Motorman on June 16, 2014, 04:43:39 PM
https://www.youtube.com/watch?v=eYOXAMuRZms
Title: Re: Glue for Aluminum
Post by: John Leidle on June 18, 2014, 08:43:51 AM
    Bringing up the etching of the aluminum is a great point.
                              John L.
Title: Re: Glue for Aluminum
Post by: Lauri Malila on June 18, 2014, 08:52:36 AM
Never used it in hobby things, only used it in my old job with satellite parts.
But I think West sells sort of a kit for gluing aluminium..? L
Title: Re: Glue for Aluminum
Post by: Dale Hymanyk on June 20, 2014, 08:19:19 AM

One improvement would be to spread the glue before roughening and use it as cutting fluid. That way the fresh aluminium surface won't get in touch with air. Oxide layer is one big factor in bad adhesion.

L

Yup. This is the correct technique for epoxy. You can also get fancy with various epoxy systems (WEST etc.) by using structural fillers that are so strong you can mould structural parts (and I have) with it. Great on boats but heavy for model planes, so use sparingly.


Never used it in hobby things, only used it in my old job with satellite parts.
But I think West sells sort of a kit for gluing aluminium..? L

We built our 20 foot Eun Mara sailboat with WEST epoxy. In my opinion, they're the best in the business. :)
Title: Re: Glue for Aluminum
Post by: Paul Smith on June 20, 2014, 10:55:21 AM
https://www.youtube.com/watch?v=eYOXAMuRZms

See?  This where ARF's have gotten us.  If the Mayalsian airliner had a modeler on board they would patched it up and flown it home by now.

-------------------

Famous quote:  "If we stop feeding the injured men now we could survive three days longer."
German engineer:  "That assumption was, of course, included in my original calculation."
Title: Re: Glue for Aluminum
Post by: FLOYD CARTER on June 20, 2014, 11:06:17 AM
"Beware of Prop" ?  By the time you get close enough to read the sign, it's too late.

F.C.
Title: Re: Glue for Aluminum
Post by: Randy Powell on June 20, 2014, 11:11:23 AM
I was looking at some stuff called Cyberbond glue that is formulated for gluing metal. Not sure how it would attach to balsa, but it looks interesting.
Title: Re: Glue for Aluminum
Post by: RogerGreene on June 20, 2014, 01:25:20 PM
Enjoyed 'Flight of the Phoenix'... :)
Roger