Will 6063 grade aluminum hold up in marine environment?

[Mark42]

For my Hardtop project, looking at aluminum U and L channels to make windows . Not knowing much about different aluminum grades, I see that 6063 is listed as "ultra corrosion resistant architectural aluminum". Thought it would be wise to ask here before ordering some. It will be used on salt water, probably painted or polished.

Also, I am looking for this window hardware or something similar in stainless or plastic. Doesn't have to be this exact design, just a manual device to hold the widow open at various intervals. I can't find it on iboats. If anyone can post a supplier, I would be very grateful.

This photo is from a Grady White project on shareaproject.com

 

[rickdb1boat]

Re: Will 6063 grade aluminum hold up in marine environment?

Mark, 5052 aluminum will do the job. Then if you want to keep the polished look, use a product called Sharkhide. It works great...

http://sharkhide.com/sharkhide_metal_protectant.htm

 

[i386]

Re: Will 6063 grade aluminum hold up in marine environment?

Reminds me of grandad's old shrimp boat. There were windows like that all across the front of the wheel house. There was a piece of 1x2 laying in each window sill used to prop open the windows. It wasn't pretty but it worked. It's funny the little things you remember sometimes.


Search for Hatch and Window "Adjusters" and I think you'll see some options.

 

[wire2]

Re: Will 6063 grade aluminum hold up in marine environment?

Have a look in a trade directory like Frasers for architectural aluminum or aluminum extrusion. Anodized will stand up much better to salt than polished or painted.

 

[Mark42]

Re: Will 6063 grade aluminum hold up in marine environment?

Search for Hatch and Window "Adjusters" and I think you'll see some options.

i386, you are right on the money. "hatch and window adjusters" is that they are called, and Sea dog makes exactly what I want in this nice stainless/nylon job:

Who would have thought they were call Adjusters???? :redface:

 

[dingbat]

Re: Will 6063 grade aluminum hold up in marine environment?

You can't bend any of the 6XXX aluminums so if you have to do any cold working the 6XXX series aluminums are out.

Ideally you want to use 5086 in marine applications but 5051 or 5052 are cold workable.

As for the finish, you'll need to have it anodized or power coated. Polishing will not last the first outing and paint does not adhere to aluminum without a lot of prep and even then paint is suspect at best.

You can use pre-anodized material but then the joints will not have any protection and will require constant up keep. Power coat is the way to go.

 

[Mark42]

Re: Will 6063 grade aluminum hold up in marine environment?

Thanks Dingbat!

So what is that soft bendable stuff available at the home centers? I've made stuff out of it before, but nothing that went on a boat. I assumed it would corrode fast on the salt. But, if I can work it easy, than powder coat, it might serve fine.

I would prefer to use 304 stainless, but it starts to add up fast when making window frames.

Maybe I'll change the design so the metal parts are not exposed unless the window is open.

 

[dingbat]

Re: Will 6063 grade aluminum hold up in marine environment?

Any bare aluminum is going to have issues in saltwater without some sort of a protective coating.

You’ll also have to worry about dissimilar metals with aluminum around saltwater. Keep it in mind when choosing your hardware and components.

 

[Mark42]

Re: Will 6063 grade aluminum hold up in marine environment?

A quick note before I leave for the weekend...

Don't have time to scan and post my drawings so I'll just describe by latest window idea.

- Assume the top is made from 3/4" foam and glass, totalling about 1" thick.
- Say the window opening in the top is 20 x 24".
- I outline the opening int the hard top with 1/2 x 1/2" angle aluminum, with the bottom leg facing the window opening, flush to the edge of the opening.
- The window is tinted plexy, about 24x28", giving it a 2" overlay on the window opening. On the underside of the plexy, more 1/2x1/2" angle is mounted with recessed aluminum screws with the leg facing outward toward the parimeter of the plexi, and only about 1/2" larger dimension than the angle on the top. So it closes like the lid on a shoebox.
- The oversize plexy will visually hide the aluminum angle. It will also help reduce water driven by wind from contact with the aluminum.
- When the window is closed, it will appear to be offset from the top by 1/2 inch or so.
- On the underside of the plexy, where the angle mounted on the hard top touches the plexy, apply 1/4" Hatch Tape (foam seal) to increase the sealing ability.
- Use two offset stainless Hatch hinges at top of the window (believe me they are expensive- thankfully I only need 4).

The window openings and windows themselves will be trapazoids, not true rectangles. Am still working out hinging options and window Adjusters on a small scale cardboard mockup I made. Models really help!

The window design is classic proven boat hatch sealing technology. One piece fits over another like the lid on a box. Water has to go down, then up, to get inside. I'm not too worried about small leakage, I can provide drainage where the hard top meets the hull. It all slopes away from the interior at the perimeter where the top will mount.

Will try to post some sketches next week. Going to the beach for the weekend to close up my Mom & Dads house. Mom is recovering from knee replacement surgery and Dad doesn't want to leave her, so I'm going to take care of things. No, I'm not bringing the boat. (darn!)

 

[MUDWISER316]

Re: Will 6063 grade aluminum hold up in marine environment?

dingbat just so you know you can bend and cold work 6xxx aluminum. i'm using 6061-T6 on my boat. your 5xxx are better for marine environment. just my $.02!

 

[dingbat]

Re: Will 6063 grade aluminum hold up in marine environment?

dingbat just so you know you can bend and cold work 6xxx aluminum. i'm using 6061-T6 on my boat. your 5xxx are better for marine environment. just my $.02!

Can it be done (R = 2 x T), yes. Is it best practice, no.

As a Metallurgist and a Design Engineer I would not recommend its usage for the requirements outlined above without sufficient knowledge and experience in the handling of the material. Even then, 5052-H32 would be a much better selection for projects that require welding and bending of the material.