Gun Blueing

[Brian Lawrence]

Hi There,
Can anyone recommend someone to do some gun blueing . Working on a 9 Cylinder radial engine (Lee Hodgson's version), and need to get the cylinders done. Apparently there are two different ways to have it done. Anyone kow anything about blueing?
Any help would be appreciated.
Thanks Brian

 

[BradH]

Hi Brian:

There are a few different methods. Most bluing is a corrosive process using salts at high temperature. Cold blues are also available - you could buy from Wholesale Sports or the like. Browning is a rust process.

There is a method - I have instructions here somewhere - of a hot blue that is not quite as hazardous as conventional bluing but considered to be "deeper" - i.e. more part of the metal and longer lasting - than cold blues. I will try to dig the info up.

There may be some new processes as well that I am not aware of.

Anyway, if you were looking for something easy on an ornamental piece, cold blue would probably work well. Basically you meticulously clean and degrease the parts, and your hands. Likely best to wear gloves to prevent oils on your hands from contaminating the work.

Put some of the bluing compound on a clean rag, and wipe it on. Once it fogs up, you will probably be directed to rinse the parts in cold clean water, and then buff them dry. Then oil to protect from corrosion. That is what I recall anyway...

Brad.

 

[BradH]

The hot water bluing treatment is called Dicropan IM from Brownells.

http://www.brownells.com/gunsmith-t...uing-chemicals/dicropan-im-reg--prod1067.aspx

Looks like they only ship to the US though...

Basic process is clean, cold water, boiling water, blue, boil, steel wool, blue, and then oil.

Have you checked Caswell metal finishes? Don't recall any bluing materials, but you never know.

Image doesn' t match product... http://www.wholesalesports.com/stor...s/Firearm-Accessories/Solid-Gun-Blue-/p/77805

http://www.basspro.com/G96-Liquid-Gun-Blue-Gun-Treatment/product/10205546/

 

[PeterT]

Hi Brian. Long time ago I PM'd this guy who built the Hodgeson-9 & then the 18 cyl.
http://www.homemodelenginemachinist.com/showthread.php?t=21601
In both cases he had his cylinders done by a gunsmith using the hot bath / nasty salt process. He claimed the typical ambient or touch-up blueing kits he tried didn't stand up well under running conditions (temp, fuel, oil...) based on some of his previous engines. I think in both cases the cylinders were 12L14 but don think that was an issue either way.

I called Shooters Edge to see if they had a gunsmith contact to maybe farm out the work. The guy I spoke with said he only did minor touch-ups using the kits, but indicated there was maybe a guy in BC. Never did make a connection. I ended up opting for a design that used aluminum cylinders so dodged the bullet.

Tell me more about your build. How far along? Built anything similar before? And here I thought I was the only radial nut in a 200km radius (starting my first build, 5-cyl glow).

 

[Brian Lawrence]

Sorry for the delay.....Computers been down...(Renovating computer room). If I had to guess I'm about 35% done. I've completed the crank case, cylinders, pistons, crankshaft, piston rods, piston rings, wrist pins, and maybe a few other little pieces. I'm finding it quite a challenge. I have very little machining experience. Although having a mill (King Canada) and a small Busy Bee Lathe (B2777) I probably should have picked a smaller project. Small in the sense that every time I really need the milling machine I can't use it because something is already there that can't be moved. The build is really teaching me that 0.001" is really a lot of metal. Hence I usually have a lot of chips on the floor, but that's OK as I usually keep the chips to melt later in the casting furnace. My experience is limited, but I built a small steam engine prior to this project. I'd include a picture but I can't find anything after my wife has set up the room again. She hid everything from me!!! Can't find a dam thing.....lol
I've been buying plans & prints from opposed 4 cylinders, inline 4's, 3,5,7,9,18 cylinder radial engines, V4 engine, Blown V8 engines. All model engines. I probably have enough stuff to keep me busy "Till I Die"
You were right by saying that the cylinders were made out of 12L14. Lee Hodgson Designer of the 9 cylinder recommends having the cylinders blued.
I'm going to try and make this weekends meet and greet at the Coffee shop, and I'm going to bring a few pieces to show everyone how bad machining can get.
I'm hoping to get tips and tricks from other hobby machinist's in this group.

 

[PeterT]

Thanks for the info. I've earmarked the coffee meeting myself. Look forward to it.