Plastic binding how to

[Mike Ryan]

I have always used wood bindings on my acoustic guitars but am trying plastic.
I got kind of bad result on one cream binding and am going to have to rout it off. Got a very jagged line where side and binding joint.
BUT what I really want to know is how to do side purfling. I have a bunch of black abs purfling and a bunch of plastic purfling strips. I have gotten the purfling to go on the top fine but have not tried on the sides.
Do you cut the purfling like a few thousands over the recess depth, then try to cram it in there with the binding and cement or some other way. I think I am having a brain freeze.

[Michael Lewis]

Often for side binding with the accent stripe (purfling) it gets glued to the binding before putting the binding on. The main difficulty is it is usually thin and tends to roll instead of bend around the curves. Much easier when it is glued firmly to the binding.

[Patrick Hanna]

Michael, I am following Mike's thread, too, and I have a further question: What glue do you use to glue the binding and accent stripes?
I know that seems like it ought to be pretty obvious, but I've never done it in plastic. Thanks.
Patrick

[Robert Russell]

I have done it a number of time and it is pretty easy.

You can make a simple jig out of scrap wood and some heavy rubber bands as the drawing below.

Then just use acetone to weld the plastic together. Start the strips out by welding about an inch of the 2 pieces together then slip it between the wood to get it started through the jig. Then just brush acetone on the 2 parts and pull it through the jig. It will weld the pieces together in just a few seconds and pull the next section through. I can weld a couple of 36" pieces of plastic binding together in about 5 minutes. When done just lay the strip flat and let it sit for an hour or so. Then you can use a scraper to thickness them. What I do is use a couple of strips of wood the thickness you want the bindings to be laid side by side with a gap between them. Put your new welded perfling strip between the pieces of wood and scrape the binding down until you hit the wood.


Hope this helps.

Cheers,
Bob

[Michael Lewis]

The acetone process works on some plastics and not for others. It is great for celluloid but not great for vinyl or ABS, so test on your materials. No matter what plastic you have there is an adhesive for it.

The illustration above shows laminating two pieces side by side, i think the question was about adding an accent stripe at the bottom edge of the binding. It works much the same manner but you put the strip under the binding.

[Robert Russell]

Acetone works great on ABS plastic. That is what I have used it on for quite some time and have never had one fail. All you have to do to prove it to yourself is just take some shavings and put them in a small container with acetone... They will dissolve in just minutes. As a matter of fact the reason I suggest using scrap pieces of wood is because you will end up with dissolved binding that you will have to scrape off the wood after a few strips. I just throw the jig away after it gets to gunky.

As for laminating the strip on the bottom of the binding... just turn the binding sideways... Done it a number of times.

Of course if you want to wast money spending $50 on a jig and special glue then by all means go ahead.

I would suggest testing the binding to be sure it will melt it. If it does melt it then it will bond them together.

Cheers,
Bob

[Michael Lewis]

Robert, thanks for the clarification. It is difficult to know what some binding plastics are, sometimes the sellers don't really know. So it's best to test on the stuff you have.

[Gordon Bellerose]

I have to agree, and confirm what Bob said.
I am in the process of gluing plastic binding on an electric guitar body, and acetone will dissolve ABS bindings in a few minutes.
I actually think you would have to be careful not to use too much when glueing strips together.

Can you confirm that for us Bob?

I have another electric body that I want to do a multi-strip plastic binding on, so this thread is just in time.

[Robert Russell]

You do have to be a bit careful because it is pretty aggressive on soft plasitcs but acetone does evaporate really fast so unless you really saturate it you shouldn't have too much of a problem. I just use a 1/2" artist's brush and slide it between the 2 pieces the length of the jig I make. Then pull the strips through, let it sit in the jig for about a minute and do it again.

I can say that what you do need to do is scrape the melted plastic from the jig after doing a few strips because you are constantly pulling the bindings through the jig and the melted plastic will come off the bottom of the strips being welded. What will happen is it will start to drag and get harder to pull the strips through the jig so you need to scrape it off and let it dry up a bit.

Another trick I have seen (but I do not use) is to use acetone to glue the binding into the channel. I tried it on some scrap wood and it does seem to stick them but I didn't feel confident enough in the bond to use it. I use Weld-On which is available at Stew Mac. I have also used regular Testors model cement which seems to be the same thing as Weld-On (at least it smells the same).

But yes, you want to try to keep the acetone between the strips. If not it will be a sticky mess trying to pull them through the jig.

Cheers,
Bob

[Gordon Bellerose]

Michael, I am following Mike's thread, too, and I have a further question: What glue do you use to glue the binding and accent stripes?
I know that seems like it ought to be pretty obvious, but I've never done it in plastic. Thanks.
Patrick

I started another post on this very topic in the Glues section.

Most of the builders in the U.S. are using Weld-on-16, which is readily available.
Here in Canada, one of the posters in that thread gave me a link where I can order it from across the country, but I haven't found it locally as Canadian environmental laws are different.

Mark Swanson told me that he has used C.A. GEL for plastic bindings with good success, so I used that on the above mentioned guitar.
So far, so good.
Keep a rag damp with acetone handy to wipe up any squeeze out while you work. The CA GEL sets up fairly quickly, so you only work about 3-4 inches at a time; less in the tight corners.

[Mark Swanson]

Glad it worked! You are right, it sets up pretty fast, but not as fast as the regular liquid CA and the liquid stuff can run all over the place.