Standardizing on One Panel Thickness
We've always used 3/4 ply for cabinet cases, and done various thicknesses over the years for the backs. I've just become aware that in Europe they seem to use 16mm melamine for everything. For example I noticed that for Blum tandems and tandembox parts the stock is optimally 16mm thick.
Now that we have a CNC router I am thinking about switching to 16mm plywood (sorry I hate melamine and particle board - dropped a cab I was nailing together on my toe and permanently mangled it in 1987 and have never forgiven melamine ever since!). We could nest all kinds of parts out of it and keep life a little simpler.
I used to think 16mm was a little thin, but if it is plywood and if we use solid ply tops and back that are 16mm, this make a pretty strong cube. Not to mention that we have come up with a way to nest fully rabbet jointed case parts all done on the flat table (no on-edge work), so our boxes really lock together well and there are no butt joints. All our cabinetry is very high end. Iím just a little concerned that all 16mm construction might be viewed in America as not high-end.
From contributor P:
I've always found the cost difference to be marginal and the selection to be less, especially with better grades of plywood. Most boxes I've looked at in Europe are made with single-sided 3mm backs. The hang rail systems won't work with anything thicker than 5mm. Itís a lot easier to move lower cabinets made with rails rather than full tops.
From contributor S:
The 16mm decision is not really about being less than 3/4", it is about having one board thickness to handle and inventory, and about nesting everything out of the same sheets: sides, bottoms, tops, backs, drawer bottoms (tandembox). I always do applied end panels so our cases are never anything other than maple/birch ply. So I may be able to order a short container of 16mm board from China at quite a cost savings.
I could also have the router cut a large square hole in the top of the base cabs (like a sink cut-out) which would still give the easier handling at install that you mention, and could be a little stronger than just stringers/rails.
From contributor M:
For case sides it is ok. For decks, tops shelves and other horizontal parts sagging is an issue that must be addressed. As mentioned before there is very little price difference and there is a big difference in availability and selection. You have a very odd reason to not like melamine. If you prefer the look and feel of plywood, I can understand that (although as a business man it makes no sense). Dropping a cabinet on your foot 25 years ago seems like a strange reason.
Unless you are not a high volume shop there will be no real benefit to you in terms of inventory reduction. Your supplier is not likely to give you any extra discount, and I am certain you will always have a reason to keep a few sheets of 3/4 and 1/4 around the shop.
The shops that are using 16mm for all case parts do so because they are very high production. You can stack more 16mm sheets on a panel saw than 18mm sheets. Also the cost difference matters to them more; $5 a sheet times 100 sheets a day - that adds up at the end of the month. For the average custom shop that processes 50 sheets a week that $250 will not make any difference to your bid price.
Like most custom shops I use three material thicknesses; 18mm for case parts, 15mm for drawer sides, and 6mm for backs and drawer bottoms. It is true that few clients would notice the difference in the case parts thickness, but I print in my marketing materials and proposals and I mention in my personal pitch that we always use 3/4" materials and that they should be aware that many of the large companies sold in big box stores are using thinner, lower quality materials. I have had clients mention in the following meetings that they noticed the differences in the competitorsí products after I made them aware. This also goes for joinery, hardware, and even the types of screws we use.
As for nesting, I nested on CNC before and now I do it on a panel saw. I do not see any difference at all in waste. The only real issue is that I process the 6mm first (these parts have no boring or routing). Then the 16mm drawer boxes are immediately assembled after they are cut. Next the 18mm parts are cut and by the time the saw operator is on the third sheet the drawer boxes are all finished and the workers all go back to banding, boring, and assembly. The result is all employees are continuously productive and there is no change over. If you are nesting on a CNC the logistics should work out the same.
From the original questioner:
Sorry, you missed my dry humor on the melamine; I said that tongue in cheek. I do very much prefer plywood for the look and feel. I like solid wood best but do not have an RF gluer to make that quick enough. I donít like the fakeness of melamine. Off-gassing is an issue too, though you can buy more expensive melamine that supposedly used less toxic chemicals to make all that wood dust stick together to make a sheet.
There is a significant difference in weight and slipperiness in ply vs. melamine. This does translate into a minor advantage over time for plywood - less strain on backs and bodies and fewer items slipping out of hands (like the cab case that got my toe). With melamine you always get the moisture bubbles when the customer gets a leak or a bottle turns over in the cabinet. These never go down when they are dry.
From contributor D:
I changed to all same thickness parts about nine months back. Everything is nested in, drawer parts, backs, everything. We went to split tops on the lowers for two reasons, easier to carry and easier to nest two small parts than one big one. No more 1/4" scraps. I was paying almost the same for 1/4" as I am for 3/4".
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