honeycomb alloy sheet and Avdels ??

[IceWalker]

Anyone know where I can get some for a half way decent price?

thanks

Jeff

[alanh]

I sure wish I knew where to get some Aluminum honeycomb at a reasonable price, but I've not found any through my net searches. I have some pieces I got at the Boeing surplus store years ago (very rare to find any these days). Really strong for the weight and thickness. Dealing with the edges when you cut it is kind of a pain as well as fastening it without localized crushing of the core. Is that what the Avdels are for? I've never heard of those.

I don't know if any of these products would do the job, or if you consider the price reasonable, but there are some sheets used in the sign business that have AL skins with various cores. They should be available at places that supply signmakers. I haven't used any of them but I'm considering the Lusterboard for a platform in the back of my Tacoma. I like the thought of a reasonably tough, smooth face and the aluminum faces to give better stiffness with thinner, lighter panels.

Lusterboard - plywood with AL skin - they say a 1/4" panel is half the weight of 1/2 MDO plywood (plywood with resin impregnated paper on the outside commonly used for highway signs) but has 85% of the strength. I saw prices around $100US for the 1/4 and $120 for 1/2. Compared to construction plywood its very expensive, but compared to good hardwood plywood it doesn't seem outrageously expensive.

Alumalite - AL face with something called corrugated polyallomer (CPA) core

Dibond - AL faces with thermoplastic core.

Alucobond - AL skin with low density polyethylene core - this one is actually aimed at architectural uses and I'm not sure where you get it.

If it doesn't have to be aluminum, there is a product called Tripanel/Marine which has marine plywood skins with a honeycomb core of the same material plastic laminate is made from.

Not an answer to your question, but it may help you or someone else who is looking for alternatives to plywood for sleeping platforms or whatever.

[IceWalker]

Thanks Alan - I'll have a look for those as well. Avdels are like a temporary rivet (I'm pretty sure it's probably a trade name) that you use to fasten the work together while you drill and rivet the piece. They are then removed and the holes used for the avdels receive a rivet as well.

I'm not to up on the aerospace fabrication piece but many moons ago had some friends that were in the business and gave me a handfull of these things

Jeff

[HenryJ]

Are these what you were referring to as "avdels"

Clecos , Panel Holding System (http://www.eastwoodco.com/jump.jsp?itemID=1219&itemType=PRODUCT)

Blind Grip Panel Holders (clecos) pack of 10 (http://www.eastwoodco.com/shopping/product/detailmain.jsp?itemID=1218&itemType=PRODUCT&iProductID=1218) , Panel Holding System Compression Pliers (clecos) (http://www.eastwoodco.com/jump.jsp?itemID=1220&itemType=PRODUCT)

[MrS]

Avdels are like a temporary rivet (I'm pretty sure it's probably a trade name) that you use to fasten the work together while you drill and rivet the piece.


I agree with HJ, that sounds like a cleco to me.

I’m guessing from your post that your looking for both honeycomb panels and clecos

Be sure to post if you find the panels. I'd really like to find a few sheets of transport aircaft flooring. :ok-kewl:

Not sure where you live but I grabbed a dozen of the ‘wingnut clecos’ here.
http://www.calaerosupply.com/


Just a little FYI there are maninly 3 types of ‘hole holding clecos’

1. The spring type like HJ posted. These are fast but require cleco pliers. These are the weakest for holding.

2. The wing-nut type, they are slow but only require fingers. These are the strongers, but can damage thin material.

3. Gun type cleco. These are fast and strong, but require a cleco gun to install.

That concludes lesson 1 of “Everything you wanted to know about Clecos but was afraid to ask” :baja_rofl:

[IceWalker]

Honeycomb Aluminium :)

http://www.panelteccorp.com/html/stockpanels.html

Jeff

[alanh]

Jeff,

Good find. Most of the people making AL honeycomb don't seem to advertise cost or availability of standard sheets even though they must make them. Not everyone wants custom made products. Now I'm wondering what it would cost to get a sheet to Seattle and if it would make it without some guy on a forklift destroying it. I should probably use the phone a bit and see if someone in Seattle distributes that kind of stuff. With boatbuilders and other people around here who must use it, I can't believe they're all ordering it and having it shipped in just for them.

I'm really trying to watch the weight of the platform/storage system I'm trying to design for the back of the Tacoma I have. I know that 0.39 inch sheet would be plenty strong enough since I have some 1/4 material and I know how stiff that is. I'm still looking at the plywood core/Al skin. I need to do some more digging to see if I can come up with some strength numbers to compare them.

How do you plan to deal with the edges and fasteners? It looks like the manufacturers can supply a lot of different materials laminated into the edges to get rid of the weak and ugly exposed honeycomb, but it looks like the only do-it-yourself option might be to fill it with potting compund. I haven't got to the specifics yet, but it seems to be an epoxy filler - probably somewhat similar to body filler.

For fasteners, it looks like you either distribute the pressure with something like a large washer or put inserts in with the potting compound. (That is unless you have a custom made panel with solid pieces built in where you need them.)

[IceWalker]

Hi Alan - i was thinking of riveting a second piece of angle aluminium to the bends. My local friendly ACE hardware store has 1" and 2" pieces of angle aluminium - in 8 ft lengths. I'm pretty sure that they can get half-round aluminum as well.

Kind of like the drawing included.

Jeff

[alanh]

Jeff,

Based on everything I've read, you.'ve got to watch out for localized deformation or crushing of honeycomb due to fasteners. Since most of the core is air and the skins of the panel are relatively thin, any compression force tends to bend the skin in toward the center. Any bending load will tend to do the same.

I can't remember where, but I came across a guide that showed some acceptable methods of fastening panels together that showed angles on both the inside and the outside. That way you have extra material to prevent the rivets from deforming the skin on the inside.

Unless you're planning something else like rivets with wide "washers" on the inside or filling the core with potting compound in the vicinity of the rivets.

Apparently, its standard practice to use a tool (Sounds like a fancy version of a nail bent 90 degrees and put into some sort of tool to spin it around.) to go in through the hole in the skins and spin it around to break the core honeycomb away to allow an area for the potting compound to fill giving a solid region to stiffen things up.

[IceWalker]

I found this book a while back - while not a definitive source it does cover some aspects of construction with honeycomb aluminium. Goes through the construction of a single seat monocoque(sp).

http://search.barnesandnoble.com/booksearch/isbnInquiry.asp?z=y&EAN=9780854295722&itm=1

Jeff