GrummanDude
Joined: 15 Jan 2006
Posts: 926
Location: Auburn, CA
|
 Posted: Mon Oct 12, 2009 1:39 pm Post subject: Metal to Metal bonding |
 |
|
I was lucky enough, last night, to get an email and learn that alodining the aft end for M2M bonding was a waste of time because it won't work. The argument was that only anodizing will work. Anodizing is out of the question. So, last night I agonized and spent 5 hours on the internet learning about all sorts of surfaces preparations for M2M bonding.
I've included the .pdf file for the Hysol 9330. This is the adhesive I chose for bonding the horizontal braces. On the second page, there is a heading that starts out ...
Bond Strength Performance
Tensile Lap Shear Strength
Tensile lap shear strength tested per ASTM D1002 after curing as shown below. Adherends are 2024-T3
Alclad aluminum treated with chromic acid etch.
Clearly, chromic acid etch is not anodizing. Read the bond strengths of the various surface preparations. The bond strength is 5,000 psi when cured at 77 degrees for 7 days. The worse case is MEK wipe only (3900 psi). The reason I made the vertical braces 3/8 inches wider was to compensate for any reduction is bonding. The thought being that, at the low end, MEK wipe = 3900 psi shear strength, the wider surface would still be stronger than the original bonded vertical brace.
This morning I talked to a structural engineer at Henkel, the supplier of the Hysol 9330, and was told that the process I did should be OK. "Should" She told me that they haven't done a lot of testing with Alodine because there isn't much call for it. BUT, she told me their results show the bond to be a lot better than with a straight chromic acid etch. Not as strong as the 5700 psi with anodizing, but a lot stronger than an MEK wipe.
I also found where B-52s, F-22s, F-16s and the like are being field repaired with Hysol 9330 using a fairly new surface preparation process, developed by Boeing, called Sol-Gen. I have a call into a Boeing engineer regarding that for use in our planes.
Gary
| | - The Matronics TeamGrumman-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?TeamGrumman-List |
|
| Description: |
|
| Filesize: |
680.49 KB |
| Viewed: |
970 Time(s) |
|
| Description: |
|
| Filesize: |
596.6 KB |
| Viewed: |
970 Time(s) |
|
| Description: |
|
Download |
| Filename: |
EA_9330.pdf |
| Filesize: |
49.4 KB |
| Downloaded: |
280 Time(s) |
_________________
Gary
AuCountry Aviation
Home of Team Grumman |
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
