Muzzle brake & Teaching a protege
I helped one of my young proteges acquire a Crosman Mendozza recently. We mounted a 4x RWS scope I had on it. Now it needs a muzzle brake with a little weight to improve it's balance. So we are making a replica of the Beeman brake out of steel. Will be painted with a durable black urethane paint.
Trued up the scrap steel bar and cut 10 grooves .114 wide (wider than a parting blade)with a profile bit I ground. This is a good exercise for folks learning to part on the lathe. You need the right profile bit, slowish spindle speed, proper feed rate, and apply cutting oil continually as the cut progresses with an acid brush. Just enough to provide lubrication to the cut. Makes a big difference and you can even hear/feel the difference. Too slow of a feed rate will cause chatter. don't be afraid to try increasing feed a little. Once you get the feel for parting you want to do it with power cross feed. Works even better. Maintains the proper feed rate which is 75% of it.
Next the center had to be drilled out. And bored to finished dimension. I'll show the boring bar later.
Here 20 yr old Tristan is cutting the tapered end with the compound slide set over about 7 degrees. Feeding by hand he is getting a very good finish. He's so big he makes my 9 inch South Bend lathe look smaller.
Now he is cutting the large 45 degree chamfer on the other end.
I'll post more as we progress on this job. What a blessing it is to have an influence on this fine young man's life. He is such a good guy he influences mine too! 😆
Raise them up in the way you want them to go and they will not depart from it when they are old
Had to bore it out from both ends. Too deep for me to do with the bar extended so far. Getting excessive chatter. Just bored about 1 3/4" and flipped it in the 3 jaw. Then bored the other end. Close enough for this job. Not perfectly concentric. Going to use two aluminum sleeves and two set screws on this one. Certainly don't want the set screws going directly into the barrel. Got a nice finish and avoided any chatter by running the spindle in back gear and slow feed for the finish cuts. Avoid chatter by slowing it down. Especially when using form bits or large radius bits. 👍
After boring I made an interference fit plug with a 5/16" hole to plug the crown end. Then faced it off. Has to be drilled and tapped for set screws and then painted. Already made one of the aluminum sleeves. Have to make one more. Ape hands 😐
Thanks for looking!
My shop supervisor would've banned me from the shop if he caught me touching a machine without safety glasses on.
I'm not your shop supervisor! But your point is well taken. Thank you. Now tell the truth, do you wear safety glasses every time you use a power tool at home? Every time you shoot your airgun? I don't always think of it because At 61 I've been wearing corrective lenses for 20 years. I'm going to go get some safety glasses for my shop visitors. 😉
Great to see you teaching skills to the younger generation!!
As for finish, I have had great luck with spray can bed liner. Practice on scrap and you can get a nice smooth finish that will stand up to use very well.
@kwk Actually I do wear safety glasses all the time when working in the garage or mowing or machining, but not when shooting air rifles. So bad on me too.
I think most of us want to manage our own risks. For better or worse.
I tried Rustoleum bed liner on a scrap. Scratches right off after over a week cure. Can you specify the brand you use, please? Thank you.
Rustoleum is the brand that I use. It requires a 100 grit surface and several light coats. I have used it with several brake barrel guns with great results.
The stuff comes out like a fire hose. I'll try on another scrap after I give it some tooth with 100. I can spray the can into a cup and apply with an airbrush for better control.
Just doesn't seem like a very hard coating. Yet. Thank you.
Make sure you shake it very well, and hold it about 12-13" away from your project.
prep prep prep is the key warm up the steel with a hair dryer or similar then wipe it down with acetone or lacquer thinner. Before applying finish rewarm. The heat opens pores up in the surface which other wise hang onto various oils and such ( causing all kinds of havoc later on), secondly it gives the finish a better grip. A toaster oven is a great way to get a finish to dry properly just set for warming. Most finishes do not do well under 65degs F. They get dry to the touch, but underneath are still setting up.
If the piece is steel, even if the endcap is aluminum: ¿Why not (cold) blue it?
Van's is not that complicated to use, three applications, finish with some Non-Detergent motor oil and it will do good.
I use Vans. Many times. Others too. It's usually a chemistry experiment to see if it will get dark enough. Or just medium blue. All steels don't react the same. Some only turn grayish. 12L14 for instance doesn't want to darken well. This part is made from scrap so I don't know what it is other than cold rolled. I might try it. Nothing to lose.
I had to take a "brake" from it I've had to work on some other things. I baked a ton of Christmas cookies because I like to! 😀 Helped this protege put a rear wheel bearing in his Subaru New Years weekend. That was a tough one! 😬 And I made the pork dinner. Also wrestling started back up and our youngest son is a sophomore at 113lb. Dad never misses a match. All 3 of our sons wrestled. At one time we had one wrestling college, one on HS varsity, and one on Junior high. 🤪 Love 'em.
This brake pictured is on an FWB 124. I wanted it black because the FWB finish is so dark. The urethane paint is holding up very well. Might not work for everybody. I'm one of those guys that vary rarely even marks the stock on my guns. I think some of the Beeman brakes were painted? The brake shown is slim and couldn't be attached with a set screw so I used blue locktite. I didn't like the look of the bulky one I had. Gave it too big of a schnozz. 🤥 And it added another inch to the lennnngth.
Chris, thanks for the advise. I often use heat to cure paint. Dry doesn't mean cured. Cure takes time. Heat speeds it up. Providing some "tooth" for paint to adhere is important. The paint I am using doesn't flake or chippl; off easily. If you take a putty knife to it it scrapes off but not all the way. It's formulated to paint car wheels. Painting is one of my specialties. I've been a professional painter 25 years. I went to trade school for machine tools. Worked in a shop, worked in auto body, and as a mechanic. That's why I'm so cuckoo! 25 years in the painting business is the straw that broke the camel's brain. 4 more years full time..........Don't rush it.
Hopefully I finish this project soon. The kid wants to complete his gun.
I use Brownells 2-part Dura Coat paint on my gun projects that require paint. It will NOT come off. It does require an airbrush to apply.
SAFETY GLASSES a most with a metal lathe
Agreed on heating up steel surfaces and giving them some time in the toaster oven to cure. Bonds well and remains durable.
Excellent write up. Always love photos of metal projects underway.
Thanks for investing the time in Martin to pass along your hard won skills and experience. You're a real mensch.