This is a tutorial on doing intarsia. At least how I do it anyway. 🙂 There are seven written steps and a video to go with each step.
Step 1. Choosing a pattern and choosing your wood. (video 1)
You can buy patterns online or buy an instarsia instruction book with patterns. A lot of places online offer a free monthly intarsia pattern. You can also use a coloring book picture, a stained glass pattern, or even make your own pattern. I have made patterns by tracing photographs. If you use one of these that are not made specifically for intarsia then you will have to be creative on grain patterns, colors, and depth of the piece.
I have found that the finer the lines the better, if the lines are too thick you can trace your pattern to make the lines thinner. Make multiple copies, keeping a master copy, and I like to have one spare to look at while I am working on the project. The amount of copies you need depends on the number of pieces there are. Make sure you choose a pattern that you like. I have bought a few patterns and now when I look at them I am not interested in making them because I really don’t care for them. Why did I buy them? I’m really not sure.
Choosing your wood is the hardest part of the project. Unless you are using the same type of wood, which you most likely will be using a bunch of types of wood.
The things to think about when choosing wood are: Color- choose the colors that you want and keep in mind colors that work together. Thickness-same thickness wood doesn’t matter because you will be shaping each piece and changing the thicknesses anyway. Remember, the thicker the wood, the harder it is to cut, but the curvier you can shape the piece. Species- Extremely dense wood is harder to cut. And I have found that wood with a lot of design in the grain can be too busy to use in a pattern.
Step 2. Attaching the pattern to the wood. (video 2)
Keep one copy to set your wood pieces on as you cut them out. I like to keep another copy to look at too. The amount of pieces in the project will determine how many copies you need. You will have to get creative on how you cut your paper pieces in order to minimize the number of copies. Cut out each paper piece and arrange them by color. If the pieces aren’t numbered you may want to do this, it really helps keep things less complicated. Attach each paper piece to the corresponding colored piece of wood. I use repositionable stick glue, but whatever glue you like you can use, as long as it is removable or repositionable. Some folks use a spray adhesive. (Update: I have tried a new technique when attaching the pattern to the wood. I put blue tape on the wood and then glue the pattern to the tape. So far it is working great! Apparently the tape lubes the blade too! ) When attaching the paper to the wood, make note of the grain of the wood and the design of the pattern. To enhance the end result, utilize the wood grain, or a knot. This can lead to some wasted wood, but with planning you can minimize waste. Bought intarsia patterns will have an arrow recommending which way the grain should go on the piece but you will have to determine this on your own with patterns not specific for intarsia.
Step 3. Sawing the project. (video 3)
Choose a blade that corresponds to the thickness of wood you are using. Also, dense wood may dull the blade quickly. Have a lot of blades. Here is a handy chart for choosing a blade.
Make sure the blade is perpendicular to the saw table. I have had this off a bit before and it really affects the way the pieces fit.
Cut along the line, or inside, or outside the line. As you practice you will figure out what you like best. When cutting with the scroll saw there will be tear out on the bottom side, which I call fuzzies. These fuzzies can be sanded off quite easily. If the tear out is on the top of the piece while you cut then the scroll saw blade is upside down. I’ve done this a lot. I like to set the pieces on the master pattern as I cut them out. You can check the fit of neighboring pieces as you go and either adjust the pieces if need be, or cut a new piece. Once the pieces are all cut out then I remove the papers, which is really exciting if you have used a bunch of different colors of wood.
Step 4. Rough shaping the project. (video 4)
I use 80 grit sanding paper on my pneumatic sander when shaping my project pieces. I love my pneumatic sander because the drum is rubber and filled with air which makes it easy to contour the wood. A spindle sander can work too it just won’t give you that give of the rubber air filled drum. I also use a pencil and mark on the piece the height of the neighboring pieces or where I can contour more. Make sure you do not use the sander on the entire side of the piece. You want the pieces to be touching, so avoid removing too much. I like to make my pieces really contoured, so I do involve the sides a little, but not enough to remove the contact. I sand each piece of the project, maybe even more than once, until I get the desired shape.
Step 5. Fine shaping and sanding. (video 5)
I like to use sheets of sandpaper and roll them up, this gives a firm but flexible surface to sand with. First I use 100 grit. This finalizes the shape of the project and takes the longest of all the shaping and sanding steps. I go over every piece to make sure it is exactly how I want it. Next I roll up 150 grit and go over everything again, this is the beginning of the smoothing process. And finally I use 220 grit, rolled up, and go over everything again.
Step 6. Gluing the project to the backer. (video 6)
One thing to think about before gluing is adding hanging hardware and possibly a signature. This is much easier to do before the project is attached to the backer. However, you can put those things on there afterward, but you have to protect the project when you flip it over. I like to use ¼ inch plywood or hardboard as my backing material. You can use whatever you like though. There are a few different ways to use a backer. One way that I like is to make the backer “invisible” because it matches the shape of the project. If you have followed your pattern perfectly then you can use a copy of the pattern to trace the outline on to the backer. If the project is shaped differently you will need to trace the project outline onto the backer. To do this I tack glue each piece together with CA glue so I can lift the project as one piece onto the backer, trace around it, then removed it again so I can saw the backer. Another way is to cut the backer into a square, rectangle, or whatever shape you like and wood glue the project to it. Then you can add a frame or whatever you wish. Once I have the backer picked out, and cut out or cut to shape, then I wood glue the project to the backer. If I have tack glued the pieces then I lift the entire project and add wood glue to the back surface. If I have not tack glued it then I add wood glue to each piece and place them on the backer one by one. A thin coat of wood glue is all that is needed, and it is good to put a layer on the backer as well as the project. I leave the project to sit and dry. Some recommend placing sand bags over the top, but I have found just leaving it alone works well.
Step 7. Applying a finish and completing the project. (video 7)
When the project is dry look it over and make sure there is no glue on the surface. If there is you can lightly sand with 220 to remove it. I spray air over the project and in between the pieces to remove any dust. Then I use a tack cloth and wipe it down. Next I spray a finish on the project. I like to use polyurethane and I usually add 2 to 3 coats, letting it dry between coats and lightly sanding with 400 if need be. There are many finishes to choose from, like everything else just find what you like! There are other ways to add a finish to an intarsia, including applying a finish to each piece before gluing the project together. Again, try different ways and do what you like.
This concludes the tutorial! I hope you enjoy intarsia!