Framing/braces or just bolt the plywood together?

Alexa · 01-14-14, 01:47 PM

I would like to build a cage or two over my spring break, and apparently have nothing better to do at school than plan enclosures and other snakey-things. The way I'm planning, the cages will be front opening, and between 3x1.5x1.5 and 3x2x2, and I'd also like them to be able to stack without the use of a shelving system. I'm planning on using some nice plywood (not OSB) and probably a marine epoxy or something similar to seal it. Though I have little experience building anything, I have a brother who is a master of everything power-tools, and with his help I should be able to manage

So my question(s): Do they need to have some kind of internal framing, perhaps made of 2x2s? Or is it sufficient to just screw the sheets of plywood together?

Any other suggestions are welcome, too!

pdomensis · 01-14-14, 02:02 PM

I've done both ways. Framing is definitely more sturdy and safer to pick up and move around, and would be safer to stack like you mentioned. That said, I think if you went with a thick enough ply (like 5/8 or bigger) so screws can bite into it, they would stand up just fine. I've got a 3x2x2 here made of 1/2 inch ply with no framing. I can feel it flex a bit when I pick it up, but otherwise it works great.

Alexa · 01-14-14, 02:23 PM

Thanks! I was originally planning on 3/4in ply, but I think if I end up doing a frame I might go with 1/2in just to cut down on the weight.

kelzerman · 01-14-14, 02:28 PM

If your building that small of an enclosure I wouldn't bother framing it. You could just use 3/4 ply and it would be sturdy as hell. Just make sure to pre-drill that plywood so you don't split it. If you can look into a rabbet joint.

Here is everything in layman's terms:

Types of Wood Joints

KORBIN5895 · 01-14-14, 02:45 PM

If you put an interior framework in it doesn't look quite as nice but it will last forever.

kelzerman · 01-14-14, 02:48 PM

Quote:

Originally Posted by Alexa

Thanks! I was originally planning on 3/4in ply, but I think if I end up doing a frame I might go with 1/2in just to cut down on the weight.

Plywood is pretty light.. About 1.8 lb/ft2 for 3/4" pine plywood.

kelzerman · 01-14-14, 02:53 PM

I will agree with korbin. With framing it will look like dog ****. If you have a brother who is good with power tools have him do rabbet joints on a table saw. After you glue and run a few screws in there it will be plenty good for what you need.

and actually if you want to take it a step further you could post laminate the exterior to hide all the screws and joints.

Alexa · 01-14-14, 05:06 PM

This is why I ask these kinds of questions here

Also, looking up rabbet joints is making me jealous of all of this woodworking. I really ought to take a class or something.

So would there be a rabbet joint at every single edge and corner, or just on the top and bottom, just on the sides, or what? With this stuff you kind of have to explain it to me like I'm five.

Thanks for all of the input from everyone!

kelzerman · 01-14-14, 06:00 PM

Just one rabbet per joint. Example: the back is captured between the two sides so the sides would have the rabbet. You would apply glue in the joint. Then screw in from the back.

kelzerman · 01-14-14, 07:28 PM

Oh I forgot to add if you decide to do the rabbet. Go about 9/16" deep that will leave you with 3/16" remaining. Now 3/4 plywood isn't really 3/4" it's a little shy. So it's more important to hold the remaining at 3/16" I can shoot you a drawing of an example. It sounds harder then it really is. To be honest if you decide to just do butt joints it will work just fine. The rabbet joint just is a little more structurally sound. If you have the equipment to do it then I would recommend that if not it's no big deal. For a cage that small you will be ok.

I'll send you a drawing of a 3'x2'x2' when I get some time.

LarryS · 01-14-14, 08:19 PM

I agree with the previous suggestions. The more complicated joinery is better depending on the project.

However, if you only used butt joints with screws it would be plenty strong. It is only a box, with no working load so there will be very little stress on the joints. Adding the epoxy would make it even stronger and seal the joinery from moisture intrusion.

It is important to make all the cuts as square and straight as possible. Plan the project out thoroughly so all the pieces fit together in the best way possible.
As said above use a drill and countersink to pre drill the holes, carefully keeping them in the center of the material.

Generally speaking the more plies in the sheet the easier it will be to work with.

If you have access to sheet PVC rather than wood, it would make the job much easier.

kelzerman · 01-14-14, 08:24 PM

Quote:

Originally Posted by LarryS

I agree with the previous suggestions. The more complicated joinery is better depending on the project.

However, if you only used butt joints with screws it would be plenty strong. It is only a box, with no working load so there will be very little stress on the joints. Adding the epoxy would make it even stronger and seal the joinery from moisture intrusion.

It is important to make all the cuts as square and straight as possible. Plan the project out thoroughly so all the pieces fit together in the best way possible.
As said above use a drill and countersink to pre drill the holes, carefully keeping them in the center of the material.

Generally speaking the more plies in the sheet the easier it will be to work with.

If you have access to sheet PVC rather than wood, it would make the job much easier.

Correct PVC is the way to go. You are talking a major price difference. I am in the process of ordering a 4'x8'x1/2" PVC type 1 and it runs $160 a sheet. That is through our supplier at work.

Alexa · 01-14-14, 08:44 PM

Thank you all so much! I was pretty sure that butt joints would work (even though I didn't know the word) but I want to do this the same way that I (try) to do everything with my pets: go a little overboard on the research before hand so that I have the best chance of ending up with something that I can actually enjoy.

I watched a couple of youtube videos on rabbet joints, and it looks like it would be pretty straight forward for someone who can actually operate a table saw. I really like the idea that these cages could be something that can last a long time, and will probably look better because of the extra effort. I'm also planning on eventually using some kind of bioactive substrate and I would like the cages to stack, so I am a little worried about what kind of load the different methods could handle.

PVC probably would be a great way to go, but it seems like for what it would cost I could just about buy a PVC cage from Animal Plastics! Which is also an awesome way to go, but I'm going to try building my own for now.

mclund · 01-15-14, 08:47 AM

Quote:

Originally Posted by kelzerman

Correct PVC is the way to go. You are talking a major price difference. I am in the process of ordering a 4'x8'x1/2" PVC type 1 and it runs $160 a sheet. That is through our supplier at work.

That's a bit pricey. Larry and I can buy it for 75.00 a sheet if we order 10 sheets at a time. Even buying a single sheet is less than 100. It's still more than plywood, but worth the extra IMO.

Matt

formica · 01-15-14, 09:56 AM

$160 per sheet is extortionate for PVCX

contact the head office of which ever brand of PVC you are using, directly, and ask them to put you in contact with your local distributor, you will save allot by using their distributor, the more companies there are between your supplier and the manufacturer, the bigger mark up you have to deal with

as for loading - aluminium profiles will deal with most load issues, anything from a simple angle to hold 20~30kg distributed, or a type6 20x40 profile which will hold a distributed load in excess of 50kg without bending (best to use the manufacturers calculations, my numbers come from my manufacturer and may not be the same for yours)

Highly recommend PVC, if you are comfortable working with wood, you will find it great to work with...and being able to pickup a 4ft enclosure with hardly any effort is really something, makes cleaning and transport much less of a chore

you can build a PVC enclosure in exactly the same way you would with plywood, except for different glues, and slower cutting/drilling speeds - or you can get creative and use other techniques which are impossible with wood, but provide a beautiful finish, simple or as complex as you like