Need ideas for building simple, light weight, strong, and inexpensive cabinets please

I need to build some very light weight cabinets that won't fall apart. I considered using ultra light MDF and even foam core panels but I'm not sure how to deal with the joints yet and perhaps there are less expensive materials, like good ol 1/4" thick plywood? Can anyone suggest how to build simple (i.e. no radius corners) light weight cabinets using relatively inexpensive materials?

Thanks

 

There's nothing light about using MDF, so skip this idea. Foam cored panels would be lightest, though the goo factor is high and round corners will be initially radused (fabric needs to go around rounded corners), though they can be squared off eventually.

Next on the list would "stick built", which in this case would be 1x1's and/or 1x2's on the corners and panel perimeters, with 1/4" plywood over the 1x2 frame work. I use this system all the time and it's fast, light and easy. I like to use rabbits on the 1x2's so the end grain is covered and protected. Stick built structures don't rely on the plywood for their strength and stiffness. The "sticks" preform this task and the plywood is just a covering, so even 1/8" will do, for half the weight.

Another method is a combination of these two. 1/4" plywood is "tape seamed" together, forming the cabinet boxes, but 1x1's or 1x2's are used for the load bearing areas, such as where the counter top lands, forming the drawer slides, etc. In this case, the plywood is part of the structure, assisted by the localized 1x2 reinforcements.

Lastly, round corners are a safety feature. The first time you bash your knee into a sharp edged corner or panel, you'll take a 3/4" round over bit to everything inside the boat. In this vain, I pre-radius the outer corners on the 1x2's, as I cut the rabbits for the plywood, so once installed, there's nothing else to do.

 

Being in the US some of my advise may not be useable but......

lightweight ply;
http://www.goldcorelight.com/index.htm

Here in Australia Paulownia timber is available in laminated panels
http://www.paulowniatimber.com.au/marine.php

Polypropylene honeycomb panels can be ordered with timber veneers, build using Par's methods. I believe similar is available is the US.
http://polycorecomposites.com/index.php

 

Actually aramid Hexcel core would be the lightest

 

I've done cabinet doors like this, (you can run the bent slats horizontally if you want) using walnut frames and mahogany slats. The slats were a little under 1/8" thick and 1" wide. They were very light weight, provided plenty of ventilation and looked 'mahvalus'. You make a frame with a slot on the inside of all four pieces, cut, sand and finish all the slats and then assemble them by positioning the the straight ones in the frame and then weaving and springing the longer ones into place. No prebending or steam bending is needed. A drum sander on a drill press along with a simple, adjustable fence (2x4 clamped to dp table) makes a very effective thickness sander.

For finishing, make them a little long and drill a hole in the end for hanging them from nails, trim to length when assembling. I usually finish with sponges or clean cloth instead of brushes, there are no drips and the finishes dry quicker and pretty much eliminate problems from dust. There are four sheens of polyurethanes, gloss, semi-gloss, satin and flat. Gloss is usually tacky looking, flat has uses but is usually special order, semi-gloss or satin looks the best and is what is used in the photo.

 

"Need ideas for building simple, light weight, strong, and inexpensive cabinets please"

How many of the ideas presented, hit all of these requirements?

Sam, those are lovely doors, maybe not especially light, though different species choices would help. I've built similar ones, with larger gaps and smaller strips.

I like stick built simply because it's easy, fast, doesn't have a heavy goo factor, the plywood is self fairing or can be finished bright, etc. Most of the time I use a combination of taped seam and stick built, with plywood panels having filleted corners on the inside of the cabinet, for easy cleaning, a few "cleats" at the hard points, like the hinge stile or counter top nailer, etc. The best looking usually have a solid wood corner post on outside corners, again which is rabbited to receive the plywood skin and finished bright, while the plywood is painted, offering some bright work to sparkle things up, yet enough painted surfaces to make things easy, in terms of effort. The last set of cabinets I made, I used 1" dowels on the outside corners, instead of dimensional stock. I cut a notch on the back of the dowel, which the plywood landed on, leaving a good bit of the dowel proud on the outside. On the inside, I just smeared a fillet the full length of the seams and called it done. There's a lot of ways to do it, but 1/8" plywood and some 1x1's are hard to beat for light, strong and cheap. To save more weight, I often will make triangular strips, from the 1x1 stock and fit these in the corners as a wooden fillet. This is half the weight of a dimensional stock, with similar strength.

Composite panels can be lighter, but also much more costly and you're fairing you butt off. If the composite panels are incorporated into the cabinet with solid wood corner posts, a pretty light and good looking deal, but again the costs portion of the OP's requirements . . .

 

Wow, great looking doors! I was wondering how to build good looking doors that would let the air flow through. Thanks.

 

My first choice was the 1 x stick with 1/8" or 1/4" ply and then I started considering other materials but I think I'll make them with the method you described.

Thanks for all the links but I'm in the US and similar materials like those are very expensive here.

I wasn't going to use regular MDF but was considering the ultra light stuff. Thank you for carefully describing this method of building cabinets!

 

A few more questions please...

1) Does anyone have more ideas for building simple light weight doors that allow the air to flow through?

2) If I go with the stick method using 1/8" or 1/4" ply, what do you recommend I finish the cabinets with?

3) Any suggestions for lightweight counter top material?

Thanks everyone!

 

Air flow can be handled very simply with holes or even just spacing the door off the face frame or "short sheeting" it top and bottom. The idea is to let air flow from bottom to top, so place holes or gaps low and high on the door or the face frame. One cool way Aktins did it on my boat, was to space the door off the frame at the bottom, but have it land on the top of the frame. The frame had slots cut under the counter top, in the face frame, but inside and under the counter top reveal. The vents aren't easily seen, unless you've had too much beer and happen to be crawling around on the cabin sole.

There are lots of ways to approach these issues and you creativity is the only drawback. As to framing size and skins, well it depends on what you want. 1/8" skins over 1x1's feels pretty flimsy, if you bang a knee into it. Finishes can be anything, though easily cleaned surfaces like paint of Formica are wise. In the end, the boat will tell you what you need. This seem pretty obscure, but the "scale" of materials can be directly related to the boat. On a 40' yacht, you could build from 3/4" oak faced plywood, hanging on 2x4 cleats with real granite counter tops. On a 22' trailer sailor, you'll think 1/8" skins over 1x1's will be more appropriate.

Epoxy some Formica to a honeycomb core and call it a day for a lightweight counter top. Not cheap, but damn light. Foam might be cheaper.

 

I like the air flow recess under the counter top PAR. It also acts as a drip guide to stop any spillage above getting further in. Similar to window sills. I did this even in my home kitchen on the worktops, seems no one else minds spilt liquids drenching their cupboards...

 

Yeah, once I saw this, I've blatantly stolen the idea and have incorporated it into other designs and projects. I had a customer tell me I forgot the ventilation holes on some cabinets I install on his Hatteras, until I pointed out where they where. I openly acknowledged his comments about my brilliance, without regard to Atkins (sorry John, I'm a pig).

 

if you need more strength you might consider a variation of the stick built, use 1x or 1x2 stringers at the corners but the plywood is made of two layers 1/8" or 1/4" plywood with expanded styrene foam glued in between. You cut back the inner layer to bond the stringers to the outer skin only.

 

How would you guys waterproof the walls and ceiling of a tiny RV bathroom that has been "paneled" with unfinished 1/8" thick luan plywood? I want the walls and ceiling to be white. Would you roll it with several coats of epoxy and add white opaque to each coat?

 

Does anyone have photos of these doors that allow the air to flow through?