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tools for making butterfly patch?

H

Hugh

Joined
May 6, 2004
Messages
666
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155
Location
Sonoma, CA
I have a number of roughed out bowls that have dried and have cracks. I would like to patch them using butterfly patches.
The question is: Is one trim router better suited for this than another? What about router guides for the pattern?
What about the pattern to cut out the butterfly and then cut out the proper space? I believe that a company makes a router guide that does both? What is the brand?
Suggestions of where to look?

Thanks.
Hugh
 
Hugh said:
I have a number of roughed out bowls that have dried and have cracks. I would like to patch them using butterfly patches.
The question is: Is one trim router better suited for this than another? What about router guides for the pattern?
What about the pattern to cut out the butterfly and then cut out the proper space? I believe that a company makes a router guide that does both? What is the brand?
Suggestions of where to look?

Thanks.
Hugh
Click to expand...

I'm pretty sure several companies make templates and guides. I'd look carefully into what the best type of router bit would be -- perhaps an upcut spiral?
 
Hugh said:
I have a number of roughed out bowls that have dried and have cracks. I would like to patch them using butterfly patches.
The question is: Is one trim router better suited for this than another? What about router guides for the pattern?
What about the pattern to cut out the butterfly and then cut out the proper space? I believe that a company makes a router guide that does both? What is the brand?
Suggestions of where to look?

Thanks.
Hugh
Click to expand...

Look at Eagle America, Woodcraft or any company that specializes in router bits. There are several different approaches to the jig. There are patterns to cut inside with a collar on the router base to make the cutout. The butterfly can be made on Tablesaw or router table. Search for butterfly template. You can also make your own template.
 
The hardest part of using a router is that you are working on a surface that is curved in three dimensional space if you are wanting to keep the cutter perpendicular to the surface. However, if you did that, it would mean that butterfly patches cut from a flat pattern won't match the cutout. A better and simpler approach would be to have the router base on a flat surface that is tangent to the bowl surface at about the center of the intended patch location. A butterfly patch looks more traditional if it has sharp corners as opposed to leaving them rounded. This means that you would also need to use a chisel to clean up the corners. Don't forget that the butterflies will need to be thick enough for the surface curvature ... and, the smaller the bowl, the thicker the patch needs to be.
 
Woodcraft has exactly what you need. I was in the store the other day and saw this plexiglass template for cutting all different size butterfly patches. There should be 2 in there that match the size for both the male and female cuts and since it's flat it will keep the router perpendicular to the bowl. I think just about any small router would do the trick. The more expensive ones simply last longer and run smoother. I have a Dewalt trim router I've used for many years but I think the bearings are starting to go it's getting noisy.
 
Check out the the article in the current AAW Journal on dealing with cracks.
There is photo and description by David's belcher of a butter fly and he may be holding the guide john talked about.

To me butterflies look better on narrow cracks and splines or rods look better across wider divides
Jerry Kermode does a nice job with the splines using a biscuit joiner to cut the slots and cutting splines on the band saw.

Have fun work safely
Al
 
In terms of routers i know the Bosch Colt is very popular as is the DeWalt. Makita makes a nice one too.

The template is used with bushings. A small bushing to cut the key and a larger bushing to cut the hole. The template is the same for both operations.

Would love to see pix of what you come up with.

Doug
 
A couple of things I learned the hard way:
  • Make sure your trim router accepts a standard sized guide bushing
  • Get a set of inlay guides (woodcraft had just what I needed)
  • Make sure your template is rigid enough that it won't bend around your vessel (again, the plexiglass one at woodcraft worked for me)
  • Hot glue the template to the vessel and go for it.
  • Have your patches cut first (make sure you use the same opening on the template (DAMHIK)
I wanted my patches to penetrate through to the inside surface of the bowl, and I prefer to do my patches when the outside of the form is pretty much at the stage where all it needs is sanding. Had to look long and hard to find a 1/8" router bit that was longer than 1/2" cutting depth. By the time you allow for the template thickness (1/4" on mine, there's only enough for a wall thickness of less than 3/16" by the time you get everything finished. (I know, I'm giving up glue surface that way, but I like the look, and none have fallen out yet...

One last thing - have a very secure method of holding your vessel while digging for the patch. I use a vacuum chuck on a Woodcut ProMount carving stand to hold the bowl while patching.
 
Thanks for the input Everyone. Good info as always.

Does anyone know if all the trim routers have the same threads on the base for the brass guides? It would be a shame to purchase a trim router and then not be able to get the proper guides to fit.

I have seen Jerry Kemode do his biscuit jointer mends. A really good idea. Jerry lives a short distance away from me. He told the woodturning club that he did not mind anyone using his technique. A good fast, neat patch really.

I just kind of like the butterfly patches. I have done a couple by hand and find it very time consuming. The big problem with that is I have about 10 bowls that developed these cracks when they were drying....and by doing them by hand would take forever.

Thanks for the info. I will look into it more. It will not be until after October when I get to mending these bowls. Too much to do right now. Fall is coming and all kind of neat things happen in the fall. My favorite time of the year.

Hugh
 
Hugh said:
Thanks for the input Everyone. Good info as always.

Does anyone know if all the trim routers have the same threads on the base for the brass guides? It would be a shame to purchase a trim router and then not be able to get the proper guides to fit.

I have seen Jerry Kemode do his biscuit jointer mends. A really good idea. Jerry lives a short distance away from me. He told the woodturning club that he did not mind anyone using his technique. A good fast, neat patch really.

I just kind of like the butterfly patches. I have done a couple by hand and find it very time consuming. The big problem with that is I have about 10 bowls that developed these cracks when they were drying....and by doing them by hand would take forever.

Thanks for the info. I will look into it more. It will not be until after October when I get to mending these bowls. Too much to do right now. Fall is coming and all kind of neat things happen in the fall. My favorite time of the year.

Hugh
Click to expand...

Most routers will use some sort of guide (PC guides are most common). Some only use thier own brand. It is not the threads, there are threads on the guide and a knarled nut to fit it in the hole. You can make or buy a new base plate to fit PC type guides. One think about the PC guides is that they lossen somewhat due to vibration. Miles Craft has a base and the guides snap into it so they do not loosen. Decide on the router and then investigate the guides it will take.
 
Gerald is right about the guides. At least on big routers there is a somewhat standard size hole that is the same as what PC uses. And if your router doesn't have a base plate with that size hole, you can make or buy one that will work. The hole isn't threaded. I also agree that the brass guides are better. The nuts seem to self-lock. The steel guides don't seem to be as smooth as the brass. I don't know if these guides will fit a small trim router. Maybe there is a mini size set of guides for trim routers. I am not really up to speed on the latest whiz bang gadgets these days even though I have about five routers not counting the router for my home computer network. 🙄
 
OK - Thanks everyone. Sounds like I will get a Porter Cable trim router and go from there.
The guides I have seen advertised have been brass. Brass is good. Now I just need to look around more closely and find a good pattern and router bit. I am sure Woodcraft or Rockler will have something.
Thanks again.
Hugh
 
Hugh said:
OK - Thanks everyone. Sounds like I will get a Porter Cable trim router and go from there.
The guides I have seen advertised have been brass. Brass is good. Now I just need to look around more closely and find a good pattern and router bit. I am sure Woodcraft or Rockler will have something.
Thanks again.
Hugh
Click to expand...

The guide intended for doing butterfly and the cutout is different. It has a cap that will offset the cut to make BF then remove and create the inset cut. (I think that is the correct order) . At any rate you do not need a whole set for this just 1 that has the cap. As I said before look in the referenced catalog or web site and they will have the needed items.
 
Hf 99552

Harbor Freight has a complete kit (#99552), which includes brass guide, locking ring and bushing, as well as 1/8" carbide bit and a centering spindle to assure concentric mounting. The bushing provides the 1/8" offset. At full extension, the bit reaches about 3/4" below the guide and bushing, which should be enough for almost anything.
 
Go to Big Island Engraving. Mark Stebbins will line you out on the whole deal. He makes many designs along with the templates. You can get the inlay kit from him or he tells you where to go to get it. MLCS has the inlay set along with a downspiral bit. Set is #9180. W the bit#9177. The bit itself #5161. Your router needs to be Porter Cable ready. Order more than one down spiral bit. If you are not going to make your own Pewas(Hawaiian for fish tail), just get them and the jig from Mark. His are laser cut and perfect. I tend to make my own and do thousands so I dont have to do them again. Have done only three batches in twenty years. When I go teach I take Marks handouts as most folks do not want to take the time and effort to make not only the patches but the jigs. I forget the issue but I have a very detailed article on Pewas or butterfly patches in an issue of Woodturning Design. When I teach I am always amazed how many folks who come to the hands on class have Marks pewas and jigs. My favorite size is the one thats 7/8ths inch long. Mark or myself are always available to help anyone who wants to get going doing these. Mark is just a friend who decided this was good as a biz decision. As all my previous teaching before he came up with his idea I just taught how to do the whole thing. Mark has made this so easy for anyone wanting to give this a go. Please note I make no money from this. I am happy to promote an easy way to make it happen. My way is long and hard but works for me.
The pewas only need to be about 1/8th of an inch into the bowl.
 
Kelly, Joe and Gerald,
Thanks for the info. All good stuff. I will get to looking it all up now and try this. I just hate to waste the cracked roughed out bowls. Especially since it is Claro Walnut and pretty good sized bowls.
Thanks again everyone.
Hugh
 
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