| 4seventy |
| (Sponsor) |
| 16/06/05 08:46 PM |
Re: homemade doubles
|
Bloodnativ,
I wasn't aware of any mud-slinging.
I think that perhaps some of my points have been missed.
I have already stated that while I may prefer a certain solder method, anyone else can use whatever solder they like.
The thing that concerns me is that there are quite a few errors in some of the statements made in this thread.
Things like...
In reply to:
Tin/lead melts at about 400 deg.F. Force-44 melts at about 600. Silver melts at 1150 to 1350. You need near "red heat" to melt silver solder and at those temperatures, molecular changes are occuring in the steel which are NOT strength-enhancing
To start with , the melt temp is not that important as solder will not be much use at melt temp.
FLOW temp is the important one.
Force 44 does NOT melt at about 600! It actually flows at 475 F.
Perhaps the writer of that info is getting confused with HI-Temp Force 44 which flows at 650 F.
Silver solder actually flows at just over 1200 F.
This is still a full 200-250 F Deg below the minimum temp required to soften or anneal medium carbon steels.
"red heat" gives a very vague description of how hot the steel actually is.
1200 F will only take the steel to a DULL red colour, 1400 F will make dull cherry red and 1600 will produce full cherry red.
In reply to:
All that the solder does is to hold the barrels into the mono-bloc, it contributes zero to the ability of the assembly to retain and withstand pressure
This one really gets me going and is totally wrong.
On any double, the join of barrels to the lumps is CRITICAL regarding the strength of the whole deal.
This is why chopper lumps are considered to be the ultimate system as the lumps are forged integrally to the barrels.
On a monoblok system the lumps are part of the monoblok and the barrel to mono solder join has to withstand the FULL AXIAL LOAD.
In reply to:
As I said earlier, Force-44 solder has a tensile strenth of 28,000, pounds per square inch. Calculate the surface area of the joint and you will find that the total joint strength is FAR in excess of the force generated by ANY rifle cartridge.
Actually, Force 44 has a MAXIMUM tensile strength of 28,000.
Its true strength, even with a good join may be only HALF that at 14,000.
Also it has been stated more than once that 4-5000 psi tin/lead solder will "do fine" but the writer wants us to do any calculations at 28,000!
This is not meant to be mud-slinging or bickering.
It is just dealing with what has been stated in this thread.
Now to avoid any confusion I'll say this again.
Use any solder you like.
For double rifle barrel to mono join I PREFER silver solder.
Why, because the tiny caress of finger on trigger ignites a 50,000 psi bomb only a couple of inches away from your face.
Think about that and then do your calculations at the 4000 psi strength of tin/lead soft solder.
You may get a shock!
