I am designing an altar for a church. The top is a typical table top 63″ long and 24″ wide. The thickness of the top and apron will be approximately 4″. This altar should be moveable by two people. It will be lifted (probably by the top) and caried down some small steps. I estimate that the weight of the entire altar in solid material will be about 150#. I would like to consider using honeycomb in the top to make it lighter. If I use this technique, it will be veneered in Mahogany. I have seen and heard of projects using this, but I do not have direct experience or knowledge of this. I have vacuum press capability that I have used for veneering. I would like this altar to last for many years, and I want to get it right.
I would like a reliable reference book, article, or other material to help me understand and choose the skin, honeycomb materieal/technique, and adhesives. I hope to be able to determine the weight savings of this approach for my application before I do all the work of making the part.
If you have any suggestions, I would appreciate them.
Thank you,
Allen
Replies
Check out this article https://www.finewoodworking.com/SkillsAndTechniques/SkillsAndTechniquesPDF.aspx?id=34006 from Fww #219. I think it may be just what you're looking for. Good luck,
Michael
Here's a Good'n
https://www.finewoodworking.com/SkillsAndTechniques/SkillsAndTechniquesPDF.aspx?id=2741
Thick tops.
The only small quantity source I know for honeycomb is http://www.vacupress.com and the thickest they carry is 1". You can build multiple layers, with 1/4" or thicker plywood between. Outer skins can be as thin as 1/4" but may sound "tinny." From experience, a single layer of 3/4" honeycomb skinned with two 1/4" x 4' x 8' plywood sheets is very light and fairly stiff but will flex if only supported at the ends. Multiple layers should be stiffer. Can't give weight specifics but I'm guessing a 3/4" layer of honeycomb weighs less than equivalent surface area of 1/4" plywood. My preferred adhesive with honeycomb is plastic resin glue for its long open time and rigidity when cured, but ambient temp must be at least 70 deg F or the glue won't cure. I'd suggest making a test with perhaps a single layer of 3/4" for experience first. Lower vacuum setting to 15 psi when gluing honeycomb; after the glue cured can bring vacuum back to 22-25 psi when veneering the skins.
You can search the veneering forum at vacupress for more info.
Thank you for your suggestions. The articles are great, and the specifics ando source o honeycomb will help also.
Thanks again,
Allen
there is 3/4" sheet aluminum honeycomb that is available out there. I have a small piece of it. they are using it here ti fit out fixtures and cabinets in boats. there is also a foam core which is also usd for boats and airplanes. wieght saving.
http://www.hexcel.com/Products/Industries/IHoneycomb is one source. I used ski's made from this stuff 40 ears ago. still have a pr of them, Hexcels
ron
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