Log dogs are a common tool to use when building log homes. They help to temporarily hold logs in place, on your wall, as you work on them.
A log dog can be purchased new for about $30 from a variety of sources, but this article will show you how to make your own for just a few dollars. Professionally made log dogs do tend to hold up a little better, because they are properly forged and have a good carbon content — but when you can make 5 or 10 log dogs for the price of 1 new one you might come out ahead just making a few extras.
Here’s an example of a store bought log dog:
There are actually different styles of log dogs:
Style A is a log dog that has blades at roughly a 45 degree angle to the cross bar. It gets driven into the logs on a diagonal in the corner, which means that you can work on the two logs where where they actually meet in the corner (it doesn’t interfere with doing notchwork in the corner). Style A is most commonly used for building Scandinavian Chinkless log homes, or Saddle Notch log homes.
Style B is a log dog that has blades set at a right angle to each other. The blades have to be driven in with the wood grain in the logs — if you try to drive them in against the grain it just won’t work. This style is used a lot when building a butt and pass log home.
Log dogs vary in dimensions:
Longer and taller log dogs work better with larger logs, shorter log dogs work well with smaller logs. There are no hard fast rules about the length of the cross bar or the height of the two legs/blades, but the above diagram shows you the common length variations. You can find them as short as 11″ – 19″, but those don’t work so well on regular sized houselogs.
The blades on a log dog tend to be long (the angle is pretty shallow).
If the angle/taper is too steep it is harder to drive your dog into logs, and it won’t stick as fast (hold as well). On the flip side, if your blade gets too thin on the end, then the edge can roll over which won’t work very well. So it usually works best to transition to a chisel edge when you get to the tip of the blade (let the blade slowly taper, then at the end give it a steep taper)
Perhaps the easiest home made log dog is made from bending and grinding rebar. Just toss some 1/2″ to 3/4″ rebar in a vice, heat it up with a torch and bend it to form a 90 degree angle. Do that to both ends and then use an angle grinder to make the blades.
Total cost for a rebar log dog could be $2, and it might take 30 minutes to make. You could do either style of log dog, just grind the legs so the blades are oriented in the direction you desire (either at right angles, or each at about 45 degrees).
Another option is to use construction stakes to make your log dogs. Construction stakes can be found at most hardware stores for a few dollars each, or scavanged at construction sites. You could also use rolled steel (or square stock), but the stakes tend to be cheaper.
Leave one stake long, and cut the other one so you have two short pieces.
One of the pieces is actually shorter than the other, by the diameter of the round stock. Those two short pieces will be the legs (or blades) of your log dog, the longer piece will be the cross bar. This would be a good time to sharpen the two short pieces, into the log dog blade shape. Just toss them in a vice and hit them with an angle grinder.
At one end of the cross bar grind a flat spot, and then weld on the shorter leg. You can make either style of log dogs using construction stakes, just weld them on with the blades oriented in the direction you want (either 90 degrees or 45 degrees).
Letting the cross bar extend past the leg gives you an extra place to hit with your hammer, to release the log dog (but this is largely a personal preference issue).
At the other end of the cross bar, weld on the other leg. This time you grind a flat spot on the leg instead of the bar.
It’s actually not a bad idea to have this leg be a little longer, for it to extend up past the cross bar. That way you are only hitting the top of the leg when you drive it into the log (again, mostly a personal preference issue, but it would also protect the weld a bit too).
You can also make log dogs out of flat iron. This next method will only make a log dog with blades that are at right angles to each other.
You should be able to pick up flat iron at any hardware store, and it will cost you about $10 for your two pieces. Sometimes you can find it at salvage or scrap metal yards.
Place the wider piece of flat iron in the vice, heat with a torch and bend to form a 90 degree angle.
Then, at the other end you blow a slot through the flat iron with a torch. That allows you to slide the other smaller piece of flat iron through the wider (bent) piece.
Then fillet weld the leg onto the crossbar on the top and bottom.
The last step is to sharpen the legs with an angle grinder.
So there you have a few different methods of making your own log dogs. These are just a few ideas, there are actually many different ways of making log dogs. You can use large bolts for the legs/blades, you can use diamond harrow teeth, or other bits and pieces of old farm machinery. The possibilities are almost endless, but one thing is for sure… you’ll appreciate having a few sets of stout log dogs when you’re building your log home, because it’s almost like having an extra pair of hands.