MikeC's bench

[Davide Sora]

12 minutes ago, MikeC said:

lol,  I did this when my wife was at work.  I was off for a vacation day!   Yes it can be done with the torch but you have to be careful not to overheat it, the temperature change happens quickly with the torch.     

Oven temperatures can vary and the dial can be inaccurate, I found that 410f is the right temperature to set it.   I tried 420 and that was almost too hot, 350 was not hot enough.  

Thanks. Using the torch, do you look at the color of the metal when it turns to bronze? I suppose you have to keep a certain distance from the flame not to overheat, and not directly above it. I don't have any experience with tempering, but I have a couple of blades that don't work, and I might give it a try.

[MikeC]

8 minutes ago, Davide Sora said:

Thanks. Using the torch, do you look at the color of the metal when it turns to bronze? I suppose you have to keep a certain distance from the flame not to overheat, and not directly above it. I don't have any experience with tempering, but I have a couple of blades that don't work, and I might give it a try.

yes, put the flame some distance away from the edge and let the heat creep up to the edge, you will see the colors change,  if you get blue on the edge it will not be hard or hold an edge,  you want to dip it in oil as soon as bronze color reaches the edge.  This is 01 tool steel, oil quench.  For something this small you might be able to quench it in water.  But it could crack if cooled too fast in water.  

Here is a picture of the finished blade after sharpening.  

[Davide Sora]

11 minutes ago, MikeC said:

yes, put the flame some distance away from the edge and let the heat creep up to the edge, you will see the colors change,  if you get blue on the edge it will not be hard or hold an edge,  you want to dip it in oil as soon as bronze color reaches the edge.  This is 01 tool steel, oil quench.  For something this small you might be able to quench it in water.  But it could crack if cooled too fast in water.  

Here is a picture of the finished blade after sharpening.  

 

Nice marking knife blade. I've honestly never felt comfortable with marking knives, I feel like they get too caught in the wood fibers with the tendency to go too easily out of track, but I probably never developed the technique needed to use them.

Thanks for the info.

 

[MikeC]

14 hours ago, Davide Sora said:

Nice marking knife blade. I've honestly never felt comfortable with marking knives, I feel like they get too caught in the wood fibers with the tendency to go too easily out of track, but I probably never developed the technique needed to use them.

Thanks for the info.

 

I don't think this style marking knife would have much use in violin making but it's good for marking layout lines when making dovetail joinery and other wood working projects.  I haven't made dovetails yet but I want to make a box to hold small items and use dovetail joints.  

[MikeC]

Here's a short video showing trimming the edges of the linings so it will be a little easier to remove the ribs from the form.  I made a new knife with a blunt tip so it won't accidently cut into the ribs. 

It's a bit of a struggle to make a good closeup video with the iphone but I'll try to do better next time. 

 

[MikeC]

I got a Japanese plane,  just a new toy to play with.  It requires a lot of adjustment and fine tuning.  

 

 

[MikeC]

Starting to work on the back plate.  This is just an initial removing of the ridge so it has a flat area to make it more stable when planing the inside surface.  Also marking an initial 18mm thickness which will be lowered after I saw out the plate outline.  

 

[ernym]

Looking Good Mike.

[MikeC]

2 hours ago, ernym said:

Looking Good Mike.

Thanks E.   

More coming soon..

I have planed flat the inner surface of the plate but I had some difficulty holding the plate stable while planing.    I glued wedges for support and used a bar clamp and my vise to hold it.   A full sized wedge under it probably would have worked better but I got it finished.   I started out using my new Japanese plane just for fun, and it worked ok but then I switched over to my old standard western style plane.     Video of all that will be up soon.

[MikeC]

ok,  here's flattening the back plate.  There's a longer unedited version if anyone wants me to post it but I thought it might get boring so I made this shorter version. 

 

[MikeC]

Marking the ribs outline on the back plate and sawing of some excess wood.  

 

 

[MikeC]

I started cutting the outline.  I decided to try the bowsaw even though I think the blade is a bit thin for cutting a thick slab of maple.   Then I decided to cut off larger sections with the Japanese saw.   Stay tuned for more. .  .   .    .  

..

 

[MikeC]

Starting to thin the plate down to the edge thickness so that it will be easier to rasp and file to the outline.   First I just trim the edges down to around 8mm so there is not so much wood for the rasp work.  

After this initial pass then it will be thinned to final thickness in a later stage.  

This is the short version.  

 

[MikeC]

This is the long version. 

I'll be making both long and short versions of the plate carving and neck carving since those take a while.

 

 

[MikeC]

Thinning lower bout and C bouts.  

 

 

[MikeC]

Rasping and filing to the outline.   I skipped the corners for now as I'm still trying to make a good template for the corner shape. 

 

 

[Sean Couch]

Right on, looking good.

I didn’t like setting the outline on my top plate but that was using a regular single cut mill file. I bought a cheap rasp and that made a world of difference. For the back, I made some tools with Perma-grit tungsten carbide sheets. Works beautifully.  

[MikeC]

3 hours ago, Sean Couch said:

Right on, looking good.

I didn’t like setting the outline on my top plate but that was using a regular single cut mill file. I bought a cheap rasp and that made a world of difference. For the back, I made some tools with Perma-grit tungsten carbide sheets. Works beautifully.  

Thanks!

Where do you get Perma grit tungsten carbide sheets?  I'll have to look that up on google.  

I found them on google search, looks like they would be good to use instead of a rasp.  

I would like to get some hand stitched rasps but those are expensive!

[Sean Couch]

I started out looking at hand stitched rasps and couldn’t handle the price, maybe one of these days I’ll buy some. It was on another thread here where someone mentioned the permagrit stuff. I think it was in the thread for Sandvik sand plate alternatives. I used the sheets to make some flat and round rasps and also a couple shaped pieces to get the edges and corners perpendicular.

I got the fine and the coarse. I almost ordered from the manufacturer in the UK to get some intermediate grits, but fine and coarse are pretty good. Ideally they could both be a bit finer, but that is me being picky. 

[MikeC]

Continue filing down to the outline, working on the corners.  

 

 

 

[MikeC]

On 5/12/2024 at 8:56 AM, Sean Couch said:

I started out looking at hand stitched rasps and couldn’t handle the price, maybe one of these days I’ll buy some. It was on another thread here where someone mentioned the permagrit stuff. I think it was in the thread for Sandvik sand plate alternatives. I used the sheets to make some flat and round rasps and also a couple shaped pieces to get the edges and corners perpendicular.

I got the fine and the coarse. I almost ordered from the manufacturer in the UK to get some intermediate grits, but fine and coarse are pretty good. Ideally they could both be a bit finer, but that is me being picky. 

Permagrit looks good, I may get that if I build more but for now I made do with a one inch dowel wrapped in 60 grit sand paper and another one wrapped in 220 grit,  for getting into the tight corner curves.  

[Sean Couch]

Yeah, for sure look into it if you make more instruments. I find that the finer grit (120) does clog up a bit, just like sandpaper. I use a brass brush to clean out the build up. I used double sided sticky tape to attach them to my flat sticks and other shapes. Easy peezy as they are quite easy to bend.

[MikeC]

Thinning the edges down to 4.5 mm 

 

 

[ernym]

Nice video Mike. Cbouts next?

[MikeC]

4 hours ago, ernym said:

Nice video Mike. Cbouts next?

Yes, C bouts next video, plus I still need to thin it down some.  It's probably still close to 20mm thick in the middle. 

It takes a while to make a back plate so it's going to be a long series of videos.