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I would like to find an adhesive to bond (on contact – without pressure) mild steel sheets (20-28 ga.) to plywood or osb panels approx. 1/2″ or 5/8″ x 4’x4′ to 4’x8′. These steel coated sheets will be artificially rusted and used for exterior wall cladding in a desert area. I want to have the steel’s perimeter bent to cover the substrate’s edges and then apply the steel to the plywood which will previously have been fastened to the wall surface. There will be a small (1/4″) reveal between panels. I don’t want to see any fasteners and especially want the sheets to be very flat with no “oil-canning”. Any help will be much appreciated.
Thank you.
John Rhone
john rhone architecture
53252 Pipes Canyon Road
Yucca Valley, CA
tel & fax: 760 365 4883
email: [email protected]
Replies
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John-
I don't believe finding the specific adhesive is going to be the hard part. Working with it once you find it probably will. If it's vigorous enough to bond, instantly and permanently, without pressure, over a large area and also flexible enough to deal with the different expansion coefficients, then wow! Sounds to me like you'd better contact NASA, something used on the belly of the shuttle probably has a similar set of characteristics. But they have clean-rooms down there.
Last summer, we worked next door to a project (pseudo-Frank Gehry-ish) that was clad with what sounds like a similar steel sheet. Two by four foot sheets were fastened along their vertical edges like standing seam roof. The field merely floated producing, I suppose, the oil-canning you're trying to avoid. One thing I gleaned after talking to some of the workers, is that the stuff is terribly unforgiving. Ladders, hammers, and anything else having physical corporeality has to be kept away, otherwise you'll have to hire Dentbusters as a sub. Sorry I couldn't be more help.
Freelance
*JohnI've had very good luck on these specials by contacting 3M Adhesives division via direct or my regional representive. They are almost too helpful, they will have a minium buy though. Sorry don't have the numbers/web info, but they are everywhere.If you have access to the material to experiment with, I think it could be chemically etched on one side and then a good adhesive/contact would do the job. The material you're listing is similar to what some billboards/signs are made of to. (24 - 28 ga.)I would also switch your substrate to 3/4" MDO Plywood. It will improve your look & functionality greatly.
*John - just read your post again,Too much movement on metal vs. wood for adhesive over surface in that sun, surface temps of metal will go from 25º to 250º and material will move greatly. I would send you to a metal fabriacation facility to resove oil can troubles. I think they will put you up in the 1/4" range and use a slotted receiver and pegs with expansion allowances.Disregard prior post, that would be a interior thought.
*What about getting rid of the ply altogether and just using steel sheet? Or even aluminum if it's artificially rusted (paint?).
*Oops, thought that was obvious on 1/4" steel.You got me.
*Just a thought from an engineering point of view. Glueing a thin closed cell foam gasket of the same size to the back of the steel sheet would eliminate the "oil can" effect. The assembly can then be hung as described by Freelance. Expansion and contraction would not be an issue with the foam but max temp rating of foam might be (should be checked with supplier). I believe there are many adhesives that can bond foam to steel and as mention above 3M is a good source. Might be a good idea to try it with a sheet and see if the sound is dampened enough for your taste. I've never done this for this application but I have glued extruded styrofoam to an aluminium skin (concept car) and I experienced no "oil can" effect.Gaby
*Not sure what the reason is for affixing light gage to plywood, like Ryan says, skip the wood all together and use a heavier gage?No expert here but...If you're bent on using light gage over panels, then how about hanging the steel without glue. Take that perimeter bend one step further and wrap it behind the panel edges and let the steel hang on the panel free floating. Leave enough play for it to expand and contract without binding on the edges. Pin the middle of the top edge (from the back) to ensure all panels move evenly so reveal doesn't get out of kilter between them.There's not much info on what these panels are to be attached to. I would tack nail the panels in position (before steel sheeting), find something solid in the wall to mount it to, then drill for a half dozen (or more) appropriate sized carriage bolts to get you through to the other side. Remove the panel, insert the carriage bolts, wrap the steel over them (bolt heads buried in the panel), place them back on the wall (maybe with a spacer) secured by a nut and washer from the inside. Of course if you're working with 2' thick straw bale walls, well...
*Hey Gaby, tell me more about that aluminum-foam gluing?
*John,Maybe these folks can help you.http://www.metl-span.com/index.htmlRalph
*cool idea - except interior is already finished. maybe i will just go to a heaver guage. all of you have got me thinking now! i really appreciate your help and interest. please keep the ideas coming! thanks. john rhone
*Gaby -Would you please elaborate on this.Thanks
*Not sure what you guys would like to know. Using foam as a core in panels has been done before. Some UltraLight builders use Styrofoam SM as the core of wing structures. It can be shaped very easily then covered with fiberglass and epoxy. It forms a rigid but light panel. I used a different version of this technique and bonded light guage aluminium sheet to a foam core that was shaped into a door panel for a vehicle that I'm currently designing. I mentioned bonding foam to a metal because I noticed that there was no "oil can" sound when I tapped on the panel. Again, I've never seen this application used in the building industry. Skin and core type panels are used mainly in the aircraft industry. These are also aluminium honeycomb cores with a kevlar or carbon composite skin (too high tech for a do it yourselfer).Variations are also emerging elsewhere like foam core building panels for example. It was a suggestion on how to get rid of the "oil canning" without having to use thicker gage steel. The foam gasket (1/2" closed cell foam) that I suggested would dampen the resonance of the thin steel thus eliminitating that sound. Wether or not it's suitable for John's application, I don't know. A further note, I bonded the aluminium to the rigid foam using contact cement. It worked fine for my application but better adhesives do exist. If you have other questions guys please ask. I'll try to answer them if I can.Gaby
*Good suggestion Ralph. I went to look at the site and it's along the lines of what I had in mind. Maybe I'll give them a call aswell.Thanks!Gaby
*Thanks for the post Gaby,I have hade several applications and installations over the past couple of years where the use of alum/stainless panels were used from art to texture on walls, didn't want to miss something. We've also had the honeycomb in a couple of walls and ceilings, I like it, yet wish it didn't rely so much on adhesives. Time will tell.
*John,I think you are inviting problems with this installation. I doubt if there is a suitable adhesive that will work over the temperature range you will need. The thickness of metal you want to use will show any imperfection, ding and dent. I don't know what you mean by artificially rusted. You probably can't find cor-ten steel in such a light gauge if that is what you had in mind. Even if you do, you are asking for problems. Cor-ten roofing is no longer marketed because of failures. If you are thinking about chemically oxidizing the panels, arresting the process and then sealing them with a clear coat, you will find that the rusting process will continue and destroy anything that thin. Think about what you are trying to accomplish aesthetically. It sounds like you want the look of heavy steel plate without the expense. When you attempt this in a light frame building, you are unlikely to achieve a satisfactory result.