Thursday, March 4, 2021

How I Do Full Tang Bolster in Stainless Steel

A picture tutorial on shaping and pinning two-part bolsters on a full tang blade. 

The bolster shape that I chose for the KN48-5 was a shape in my bolster patterns

Starting with some flattened 3/8" 416 stainless steel bar stock I rough cut the basic shape on the band saw. With some layout dye and a scribe I mark the final shape on the steel. Then bring them close to the line on the belt grinder. 





I use the tang bolster pin holes in the tang to drill and check the pin alignment. I cut  two pieces of  plain old 1/8" steel rod as temporary pins to hold the two bolster piece together while they are shaped. 


Here I used a 2" diameter wheel to shape the backs of the bolster pieces. Keep an eye on squareness and symmetry. 

Using the 45° table, I cut the bevels in the bolster. I have to careful to preserve symmetry, so I alternate left side and right side. 
Yes, I am wearing band-aids as I feel they give better grip when wet and reduce the pain on the fingers from heat build up. This little block of steel will get hot. Have a bucket of water handy. 


Once the bevels are worked to 120 grit, I will put them on some flat sand paper and lightly work each side to remove any lateral scratches. I will sand to 220 and 320 in this manner. We want no visible large  scratches.


After 400 or 600 grit I go the buffer with green compound. Only polish the fronts. The rest of the faces will get finished when the scales are on.






I cut the pins to be 1/4" longer than the the tang and bolster pieces all added up. In this case, I make them stick out 1/8" on each side. For these pins I will use the real 416 stainless pin stock. It's important to use the same material as the bolster pieces as this helps hide the pins. 


Pins are given a quick rough up with 220 grit sandpaper and bolster pieces get soaked washed in acetone. 








I make sure the insides of the holes are cleaned as well. I cannot stress enough how important clean pins and holes are. Clean the ricasso area of the blade as well. No grease and no grit allowed. 

I dry the parts and assemble the bolster and give the pins a little peening with a hammer to keep them from slipping in the holes. I carefully place four #6 flat washers and head over to the hydraulic press. 

The press squashes the pins a little first then it hits the washers. These act to press the bolster together and hard against the tang. I crank it a full 20 tons or whatever the max a "20 ton" hydraulic press will do. 



The result is the pins are expanded and the bolster pieces are super tight to the tang. If everything is flat you'll have nice lines around the pieces with no gaps. 


A quick zip on the belt grinder and the pins dissolve into the bolster. 




From this step, I will fit the scales and liners on. After glue-up I will shape the bolsters round on the top and bottom to fit the fingers.








Dan

Saturday, February 27, 2021

KN48-5 8" Chef's Knife in 154CM

The latest from the workbench. An 8" chef's knife made from 154CM stainless cutlery steel and polished stainless bolster. The scales are stabilized and dyed poplar burl.  





Saturday, February 6, 2021

DIY Belt Grinder Kit for UK/Europe

DIY Belt Grinder Kit Available for UK Makers

I wanted to let my friends in the UK and Europe know about a great DIY grinder kit that can get you up and grinding with only a little welding. Made for 2"x72" belts, but also 50x2000 mm belts!  

The packages feature precision cut parts made from 10 mm thick steel, so it's very solid. Designed with ease of assembly in mind. Parts interlock for accurate, square results. 

Kits are sold with or without wheels, and there's single phase or three phase motor options. Everything you need for building a professional calibre grinder at a fraction of the cost.

Check out Gundog Forge on eBay.

Disclosure: To support my blog, I occasionally offer products and receive compensation from vendors who are making great products of interest to fellow knifemakers. This helps pay for web hosting and projects that I am working on and will be sharing with you soon!

Grind on,

Dan

Friday, December 18, 2020

KN45-2 Big Chef

Here's a big 9" chef in CPM154 with a beautiful piece of stabilized Amboyna burl for the handle. The tang extends into the handle and is threaded so the whole thing is screwed together and the nut hole is plugged. The bolster is composed of stainless steel, brass and onyx-abalone reconstituted gemstone composite. 



Thanks for looking,

Happy Holidays!

Dan

Friday, November 6, 2020

KN73 Nitro-V in Blue Curly Maple

This is a KN73 chef's knife made from 3/32" Nitro-V steel dressed in blue curly maple scales. I made the grind line in an arc on the flat platen of the belt grinder by applying the right amount of pressure at the right time. 

 




Saturday, October 31, 2020

KN76A - Hidden Tang Kitchen Utility in CPMS35VN and Desert Ironwood


Not every kitchen knife needs to have a great big blade. In some kitchens, a nimble medium sized knife takes on all the day-to-day chores. 

This type of knife is smaller and lower profile than a chef's knife, but will have a similar length handle for a familiar work feel. Ideally, the kitchen utility will be lightweight and the balance point will be dead-on pinch-grip point. 


This blade is 6" long and asymmetrically ground, meaning the right side is beveled but the left side is relatively flat. Being asymmetric, the blade geometry pushes the thing being sliced away from the right handed user.











As desert ironwood is very dense, to get the balance right, I have used some dense materials like stainless steel and copper at the bolster. The hidden tang and a stainless steel screw extends secretly way back into into the handle. The back end of the handle is drilled with a Forstener bit to accept a special nut, allowing the handle to be tightened up. The hole is plugged with a tapered plug and epoxied. 

Thanks for looking,

Dan