As requested, a quick "how to
" on my methods for using balsawood for fencing. I'm not going to get into the debate over whether balsa or basswood is better, simply to say that I prefer balsa, as it is quick to work, economical, and extremely versatile; others will have their own preferences.
I work almost always with sheets of balsa, which come in 10cm by 100cm sheets here in the UK, it may vary elsewhere (it's often 4" x 24" in the States - ed.). The advantage of sheet balsa over strip is you do not have to stock as much -- just a few thicknesses, and from there, you can cut any size strip you need. It's more economical this way.
I have tried to photograph each step of the process, so those on slow connections, my apologies, this may take a while to load. OK, here we go.
The first thing is to decide the height of your fence, for this exercise, I have gone for 80mm, which equates to roughly six feet high in 1:22.5. Starting with a sheet of 5mm thick material, cut a piece 80mm long from one end of the sheet, cutting across the grain. This will be used to form the fence posts.
Then using an engineer's square, cutting along the grain, separate off 5mm wide sections, which will give 5mm square fence posts.
Taking a sharp knife, kept at a very shallow angle, gently shave off the corners of the posts to round it off slightly. This is not needed if you want a newish looking fence.
Then cut off at a slight angle on one end of each post, this is done on the real thing to allow rain water to run off, rather than sitting on top of the post and soaking into the grain of the wood. That's the posts finished for now, put them to one side.
Now on to the vertical boards of the fence, the same technique as used in Step 1 above, only this time using a thinner material, I used 1.5mm thick, but 1mm would have been better. After cutting off the required length for the height of the fence, use the engineer's square again to cut along the grain to separate the individual boards, I used a width of 8mm here.
There is no need to cut all the way through the balsa as I hope this shows, a quick pass with a sharp knife will go most of the way, then it can be simply snapped into the individual pieces.
Once you have enough pieces, try a dry run to check how the pieces fit together. Best to do a few extra pieces, just in case. For a new fence, you could almost stick it together now, but I'm sure that's not what most here want, so onward.
Taking the vertical boards, first take off the corners as with the fence posts in Step 3 above, just a thin slither. At this stage I like to put in a bit of character to the wood, I use an old needle with a blunted end, held in a pin vice, to put a bit of extra grain into the wood. Only light passes along the grain of the wood are needed, this process adds to the strength of the balsa as well, something to do with triangulation of the surface. Sorry it doesn't show very well in the pic, it will show more when we get to the staining.
Using the same tool still, exert a little more pressure indenting at the ends, this will cause the balsa to split and tear. Doing it this way gives a more natural effect, than if using a knife. Dont overdo this, only a few pieces in a length of fencing is enough, too much looks contrived.
Once you have weathered all the pieces in this way, try them together to see if you like the appearance. Now we get onto the messy business of staining.
Thought I would include a shot of the type of dye I prefer. Although not the same colour, this can of dye is the same type. This is a spirit based dye, which I dilute approximately, one part dye to ten parts white spirit. The jar on the right, I have been using for more than ten years, every so often I add a bit more spirit to make up for evaporation. It started out as a Black Oak coloured dye, with a touch of Pine added to ease down the black a bit.
One thing about balsa is that it absorbs stain very quickly, for this reason I paint on the stain with a brush, rather than dipping it in the stain. This prevents it from getting too intense a colour. After painting the dye on, place the piece on three or four layers of kitchen towel, this will absorb the excess stain.
Leave the pieces to soak in on the kitchen towel for a couple of minutes, then use another piece of towel to tamp the pieces and remove any remaining stain.
Here you can see that the pieces on the left have had the excess removed using the pad of kitchen towel, while those on the right are still shiny and wet with the stain.
Once all the pieces have been treated, set them aside to dry. They will be workable in about three to four hours, but won't fully dry for a couple of days.
Now for the final assembly. The temptation here may be to do a really run down fence, with nothing square, but this does make life difficult if you want to join together a long run of fencing. I keep things reasonably square and find the grid printed on a cutting mat very useful. First lay out your pieces, here we have two panels which will be joined together, so laying them out as one will help to get them to join. A cheap plastic rule is a good tool to hold the pieces in postion, while you glue on the cross pieces.
Here the two panels with the cross pieces attached. For gluing I use an ordinary white glue.
The last job is to fix on the fence posts, the central one goes over the join of the two panels, holding them securely together. With this type of fence, the vertical boards are normally not in contact with the ground, to prevent them sucking up moisture from damp ground, so mount the post to give a slight gap at the bottom. This will show in the next pic.
And so to the final shot, you can just about see the gap under the fence and maybe a little of the daylight showing through between the boards. Note also the slight angle on the top of the posts to shed rainwater. Although it probably won't seem like it from this long essay, this fencing does go together very quickly, waiting for the stain to dry is by far the longest part of the process. I hope this will prove useful to some of you that have reached this far, feel free to ask if there is something you are not sure about.