# 2x4 wood movement and joinery



## needmorecoffee (Jun 27, 2014)

I'm building a workbench similar to this one: https://www.youtube.com/watch?v=JTxbcf9zI5o

At the 4:10 mark (link to that time), you can see the joint he's planning, which he then secures with screws at the 6:56 mark (link to that time). Similar joinery at 9:57 for the lower frame ((link to that time).

He uses only screws for these joints. I was thinking of using glue + screws for a stronger joint, but it occurred to me that by having 2x4's perpendicular to one another, securing them with glue may cause a problem if the 2x4 contracts/expands along its width while glued to another 2x4 along its length.

It's only 3.5" wide wood, so not a lot of movement, so I'm thinking screws should be fine, but seems that glue would not allow for any movement at all. Should I stick to screws only?

The plywood top gets screwed into the upper frame 2x4's that are on edge so the top will just move up/down very slightly as the 2x4's contract/expand - no problem there, correct?

This workbench will be kept outside under a covered roof, so it will be exposed temps/humidity cycling. It's untreated SPF that will be painted with acrylic paint.


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## BernieL (Oct 28, 2011)

You can go and glue them... it shouldn't be a problem. Before I learned about wood movement, I started making a vegetable bin for our church Christmas bazaar and people liked them so much I started making them every year. I basically make a 2X2 frame with wire mesh on the bottoms of each compartment and wire mesh for the back. I then nail and glue 1X12 for the sides and 1X4 on the front with doors. I made the 1st onhe for my wife 14 years ago and it has had no issue.


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## TimPa (Jan 27, 2010)

on a bench expected to take a lot of abuse, I always use carriage bolts on the frame/structure joints. they can be snugged up over time if needed, and are considerably stronger than screws/glue for this application.

I just use screws to hold the top down.

not sure I would pain it, I think the paint would need maintained over time. I would just apply an oil or stain/sealer.


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## BernieL (Oct 28, 2011)

I'll second the "no paint"... if you clamp a workpiece on a painted surface you may end up having paint on it. My workbench top is a simple 1/4 inch thick hardboard from Home Depot. Inj a couple of years, I'll probably replace it with a new one for $10.


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## needmorecoffee (Jun 27, 2014)

BernieL said:


> I'll second the "no paint"... if you clamp a workpiece on a painted surface you may end up having paint on it. My workbench top is a simple 1/4 inch thick hardboard from Home Depot. Inj a couple of years, I'll probably replace it with a new one for $10.


Is it stored outdoors?

I'm planning to use hardboard over a plywood top and my understanding is hardboard would absorb too much moisture if left untreated outdoors. It would be mostly sheltered from rain by an overhead roof, but otherwise exposed to the elements.

That said, if it would survive 2 years, I'd be inclined to leave it unpainted and replace every couple of years.


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## needmorecoffee (Jun 27, 2014)

TimPa said:


> not sure I would pain it, I think the paint would need maintained over time. I would just apply an oil or stain/sealer.


The legs will get hit with rain during thunderstorms (via driving winds pushing rain sideways underneath covered roof), so I'm not sure oil will hold up as it doesn't form a barrier.

Paint seems like less work than stain and varnish. Two coats of combined primer/paint and done. As compared to sanding coats of varnish. I prefer the look of stain+varnish over paint, but too lazy to do the work required!


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## TimPa (Jan 27, 2010)

needmorecoffee said:


> The legs will get hit with rain during thunderstorms (via driving winds pushing rain sideways underneath covered roof), so I'm not sure oil will hold up as it doesn't form a barrier.
> 
> Paint seems like less work than stain and varnish. Two coats of combined primer/paint and done. As compared to sanding coats of varnish. I prefer the look of stain+varnish over paint, but too lazy to do the work required!


the type I was referring to would be a deck stain (outdoor) you just paint it on.


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## needmorecoffee (Jun 27, 2014)

TimPa said:


> the type I was referring to would be a deck stain (outdoor) you just paint it on.


Yeah, that would be as easy as paint.

I think deck stain is designed for use with treated wood. I'm using untreated wood, so I'm thinking it makes sense to err on the side of extra protection.


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## NickB (Sep 24, 2013)

Nope. You can use deck stain on almost any wood.

I have some saw horses that I made out of plain old 2 x 4s that I've left outside all year for about 3 years now. They're pretty much fine except that the bottoms where they sit on the concrete are starting to rot a bit. They probably got another 3-4 years, though. They do have a generous coating of overspray on part of them, though


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## Brian T. (Dec 19, 2012)

Finish it as you like. Throw a tarp over it when not in use. Rope through the grommets to snug it down. Another thing. Birds will only crap on uncovered tables. One more thing to wipe off. Use a tarp and it will never be marked.

My unfinished garden tables are weathered but a cloth dresses them up just fine.


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## needmorecoffee (Jun 27, 2014)

NickDIY said:


> Nope. You can use deck stain on almost any wood.
> 
> I have some saw horses that I made out of plain old 2 x 4s that I've left outside all year for about 3 years now. They're pretty much fine except that the bottoms where they sit on the concrete are starting to rot a bit. They probably got another 3-4 years, though. They do have a generous coating of overspray on part of them, though


Thanks, I think I'll go with stain over paint since it allows the grain to show through.

What's the difference between a stain like this: Olympic Wood Protector Redwood Naturaltone Semi-Transparent Exterior Stain

and a stain + sealant like this: Olympic Maximum Cedar Naturaltone Semi-Transparent Exterior Stain 

Obviously the latter has a sealant, but what's the practical difference? The stain is waterproof, so what more does a sealant add?

Is there a tactile difference - i.e., is one more tacky or slick than the other?


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