×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

ANODIZED ALUMINUM

ANODIZED ALUMINUM

ANODIZED ALUMINUM

(OP)
I would like to make a anodized aluminum t-top for my boat. I am an expirenced welder with GTAW & GMAW processes. Does anyone have any tips i.e. what process to use, bending anodized pipe, what not to do, ect.

Thanks

RE: ANODIZED ALUMINUM

I've made a few aluminum rails and in my experience the rail has to be anodized after fabrication due to the fact that heat or bending will crack or cause the anodized surface to fail. If any welding has to be done after anodizing, the surface will have to be redone, granted, I have cheated by coating a small area with clear laquer the occasional time...Mike

RE: ANODIZED ALUMINUM

Mike is correct about the anodizing near a weld.  Also significant is that the grain structure and tempering of the aluminum are changed near a weld, enough so that allowable stresses near a weld are significantly reduced from the unwelded condition.  The net result of this... for instance, if you use a 6061-T6 tubing and weld it, the result near the weld will no longer be a T6 temper.  Depending on many factors, it could be anything from a "dead soft" to T6 or other condition...you just don't always know, so therefore the reduction in allowable stress near welds (by code, within 1-inch of the weld).

RE: ANODIZED ALUMINUM

Also be aware that different welding filler metals accept anodizing differently.  Volume 6 of the ASM Handbook, "Welding, Brazing, and Soldering" does a good job describing base metal/filler metal combinations that will anodize uniformly and give a good cosmetic appearance.

RE: ANODIZED ALUMINUM

It is done all the time.  We are about to mod a tower ourselves.  I haven't welded aluminum much so I can't offer any details.  The guys I seen doing it are using TIG with a pulser.  The shop I am familar with bent it using a hydraulic cylinder pushing a radius tool (shaped for the pipe OD) against some rollers (shaped for the pipe OD).  The bend radii were always big (4 or more diameters).  They used an airbrush to touch up the welds with clear or the color of the top (they did a lot of black).

What others have said about strength at the welds is correct.  Use good design to overcome this.  Try to avoid transfering bending moments through the joint.  If you have a smaller tube Tee'd into a larger it will have a tendency to punch through the larger tube.  You can over come this a few ways: 1) put the small tube all the the large one and weld on both sides (hard to make look good); 2) put a sleeve (larger tube) around the joint in this area. Number two is how you see most "T" tops done.  It is also good at coupling out a bending moment.

Another point:
Everyone puts S.S. hardware on there aluminum tops.  The result is a galvanic cell that corrodes quickly.  Where you can, insulate (electrically) the S.S. from the Al.  Use plastic washers and bushings.

Good Luck, hope it comes out well.

BTW, We are looking at alternate coatings for the top that will resist the salt water (spray) better.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Resources

Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close