Aluminium Angle Profile on Colorbond Steel?

Aluminum to colored steel is very difficult to do reliably, without mechanical fasteners.

Adhesives might work, but judging by your description of things, you will have difficulty doing this job properly.

Go to your favorite hardware store and ask for help to do this job.

As #1, lyn, has stated you could have problems with mechanical fasteners. For the adhesives he mentioned you should contact reputable adhesive and epoxy manufacturers and ask them what they would recommend. Talk to their tech service or product development lab and describe the situation. If they don't have a good product ask them to recommend one from a different manufacturer. They want your future orders so they will help you if they know of some products by others.

A good place to start would be Henkel's Loctite division. They make many products such as epoxies, adhesives, thread sealants, caulking, etc. They have many structural adhesives such as

Loctite® H8110™ Speedbonder™ Structural Adhesive is a two part acrylic and a fast fixture version of H8000™. It is an excellent structural metal bonder especially for aluminum. The product fixtures in 5-10 minutes on steel and contains 0.015" glass spacer beads to prevent over-clamping of assemblies.

Their are numerous other products that will fit your application.

Good Luck, Old Salt

What material are the prepainted rivets? I think you can assume that if it works for colorbond it will work for aluminum profiles. Maybe use coated screws and plastic washers.

What environment is this trailer in? Are you close to the sea to fear excessive corrosion? Humid? Wet?

If you use an adhesive, you will need to strip the paint from the area to which you are bonding the aluminum. Otherwise you are bonding to the paint and you will lose the strength of a direct bond.

Depending on the shape and accessibility a small wire brush in a 4-1/2" grinder, a drill with either a wire brush or sand paper pad, or even a orbital sander would readily remove the paint and create a slightly uneven surface that the adhesive could bond to. For small areas a Dremel with a wire brush or sanding paper would also work.

Although most adhesives don't, some will migrate through the paint and attach to the substrate under the paint. I wouldn't recommend that in this case.

Adhesive formulas cover about any possible use. I worked in the adhesive industry and the most unique product field test several others and myself went to see in use was an adhesive that my plant made and used for holding the "pasties" on stripper's breasts at an adult bar/club. Unfortunately the development lab manager got to test the adhesion, not me!

I am going to assume you mean using the alumium angle to flash the corner joints?

If so, just pop rivet the ally angle to the colourbond.

If your worried about electrolysis between dissimilar metals, just buy some 1mm thick insertion rubber, cut to the width of the angle and place it between the ally and colourbond prior to riveting.

You could try this type of product

http://multimedia.3m.com/mws/media/441448O/vhb-tapes-design-guide.pdf?fn=70-0709-3830-6.pdf

See pages 12 and 13, and then give your local 3M representative a call for the best advice.

Good luck with your quest.

Do you live near the sea? if not I don't think electrolysis will be too much of a problem.

Most have gone off topic and told you HOW to attach the angle.

Guys, the question was "Will electrolysis corrosion be a problem?" Not "How should I attach the angle?"

When I worked with military stuff years ago, they used pop rivets but dipped them in a non-setting paint (can't remember what it was called) to keep moisture out of the joint. If using adhesive you would have to key the aluminium surface as well to ensure a good joint.

Here we install the rivets 'wet' with zinc chromate primer.