ER70S6 vs RG45

[Mike Switzer]

I was getting a couple other things from tinmantech.com & I noticed they sell ER70S6 for welding 4130 instead of the RG45 that I have seen recommended elsewhere.

Since I was getting other stuff anyway I bought a pound to play with, this is what they say on the website:

"Our filler rod for 4130 Chrome Moly is NOT 4130 alloy. Rather, we offer what engineers, welders, and experience shows to be the best choice for welding structures of tubing and sheet: ER70S6. I know we recommend something a little different on the 4130 Airframe Video, but I can't help making little improvements as I discover them, or as they become available. So it is in this case. This filler has great penetration and little spatter, flows evenly, and is reasonably priced."

Anyone have any opinions on the difference between the 2?

[Sam Buchanan]

I was getting a couple other things from tinmantech.com & I noticed they sell ER70S6 for welding 4130 instead of the RG45 that I have seen recommended elsewhere.

Since I was getting other stuff anyway I bought a pound to play with, this is what they say on the website:

"Our filler rod for 4130 Chrome Moly is NOT 4130 alloy. Rather, we offer what engineers, welders, and experience shows to be the best choice for welding structures of tubing and sheet: ER70S6. I know we recommend something a little different on the 4130 Airframe Video, but I can't help making little improvements as I discover them, or as they become available. So it is in this case. This filler has great penetration and little spatter, flows evenly, and is reasonably priced."

Anyone have any opinions on the difference between the 2?

I can't compare the two fillers but I did purchase ER70S6 based on the Tinman recommendation and used it to oxy weld my Legal Eagle fuse. I was very pleased with the results.

[Mike Switzer]

That is good to know. I will play with it some & see what happens.

First I have to try to fix a cast iron bearing housing (that was what I was originally getting was some flux & cast iron rod)

[Aaron Novak]

That is good to know. I will play with it some & see what happens.

First I have to try to fix a cast iron bearing housing (that was what I was originally getting was some flux & cast iron rod)

This is one of only a couple situations where Kent and I differ. I personally do not like using electric fillers for gas welding, mainly due to the electric fillers having alloying elements not needed in the OA process. I believe you will find MORE sparking and such with the electic fillers, at least I have. RG45 is a good basic use material, RG60 makes some beautiful sound welds that loot almost "buttery". From a strength or fatigue standpoint there should not be an issue either way, the ER70 series lines up pretty well with the RG60 in the performance of the finished weldment.

[Max Torque]

Best thing to do is to check with the American Welding Society and/or tech support at Lincoln and/or Miller. I did with Lincoln & Miller - being sure they clearly understood I wanted information for oxy/acetylene welding - and, after they checked on it, was steered in the ER70S-6 direction, but they said RG45 works fine too albeit with a bit lower tensile strength. RG45 is a bit easier to weld with. I've used, and still use, both, but RG45 mainly for gas. (I weld MIG, TIG, & oxy/ace.)
EAA video addressing gas welding filler rod:
http://www.eaavideo.org/video.aspx?v=1553988082001
Looks like R-65 is the filler rod of choice.
Tom

[Mike Switzer]

RG45 is a good basic use material, RG60 makes some beautiful sound welds that loot almost "buttery".

Would that be the silver colored rod that we used in the Sportair workshop I took a few years back? I know we started with RG45 then switched to something else, there was quite a bit left over & they didn't want to haul it back so most of us took some home to play with. I still have some of the coupons & short pieces of tube left over, I think when my new torch gets here I will try using both side by side & see what they look like.

[Neil]

RG(think Rod-Gas) 45 and 60 are usually considered O/A wire and ER(think Electric Rod) 70 and 80 Tig wire. This is at least how I view the difference.

While the RG45 shows to have the lower overall strength of these wires, if proper technique is used the tubing will still fail before the weld.

As I've grown older and less steady I find O/A more forgiving of my shakiness than TIG. Unless I can get braced up really well on a TIG project I seem to be forever sticking the tungsten.

[Max Torque]

Neil, good way to view and remember the differences. What you said about overall strength is right on the money - the tube will fail before the weld.

Since there are no FAA certified welders, let's go to the place that actually does certify welders for input on filler rod - The American Welding Society(AWS) - and see what they have to say...
AWS sums it up nicely in their handbook and AWS specifications (AWS5)
From AWS’ Welding Inspection Technology book (Chapt. 3)
" ’ER’ designates the wire as being both an electrode and a rod, meaning that it may conduct electricity (electrode), or simply be applied as a filler metal (rod) when used with other welding processes."
and
“The ‘R’ designates it as a rod,‘G’ stands for gas”
However, when we go to pertinent parts of AWS5 (AW5.2 and5.18) we see the following tidbits:
“The welding electrodes and rods classified under this specification are intended for gas shielding arc welding, but that is not to prohibit their use for any other process for which they are found suitable.”
and
“The welding electrodes and rods classified under this specification are intended for oxyfuel gas welding, but that is not to prohibit their use for any other process for which they are found suitable.”
ER70S -2 and -6 are suitable for OFW welding 4130 tube. Are they the best for the application? Perhaps not, but they are suitable. However, RG45 or RG60 or RG65 are more suitable.

Cheers and Happy New Year!
Tom

[Aaron Novak]

Neil, good way to view and remember the differences. What you said about overall strength is right on the money - the tube will fail before the weld.

Since there are no FAA certified welders, let's go to the place that actually does certify welders for input on filler rod - The American Welding Society(AWS) - and see what they have to say...
AWS sums it up nicely in their handbook and AWS specifications (AWS5)
From AWS’ Welding Inspection Technology book (Chapt. 3)
" ’ER’ designates the wire as being both an electrode and a rod, meaning that it may conduct electricity (electrode), or simply be applied as a filler metal (rod) when used with other welding processes."
and
“The ‘R’ designates it as a rod,‘G’ stands for gas”
However, when we go to pertinent parts of AWS5 (AW5.2 and5.18) we see the following tidbits:
“The welding electrodes and rods classified under this specification are intended for gas shielding arc welding, but that is not to prohibit their use for any other process for which they are found suitable.”
and
“The welding electrodes and rods classified under this specification are intended for oxyfuel gas welding, but that is not to prohibit their use for any other process for which they are found suitable.”
ER70S -2 and -6 are suitable for OFW welding 4130 tube. Are they the best for the application? Perhaps not, but they are suitable. However, RG45 or RG60 or RG65 are more suitable.

Cheers and Happy New Year!
Tom

One bit to keep in mind when looking at electric vs. OA fillers, is that the strength classifications are not directly comparable. They are rated differently under different situations and the actual number should be taken with a grain of salt. When you interalloy the fillers with the base metal durring the welding process, the resultant strength of the weld deposits are not that different, and in the case of gas welding are much higher than the fillers rating. You are not going to have a strength concern in a typical homebuilt with any of the mentioned fillers provided everything else about the joint is correct. However.....there are times when in the design of a specific part, a filler of a specific class is needed, and this is usally called out on the drawings.


The sport air shops use both 45 and 60. 60 is the bare filler previously sold under the name Linde #1 HT ( High Test ), and Linde Planeweld (which in later years became one of the first Tig fillers to be used in the aviation industry).....pretty cool eh?

[Mike Switzer]

However.....there are times when in the design of a specific part, a filler of a specific class is needed, and this is usally called out on the drawings.

Many years ago I worked for a company that designed air & hydraulic lifts, tilt tables, etc. for automotive assembly lines. They made me the structural / welding engineer & I had to do that on occasion. I had an old copy of the Lincoln Electric Weld Engineering manual that made things a bit easier, and some dirty rat stole it from me when I was at a later job.

The sport air shops use both 45 and 60. 60 is the bare filler previously sold under the name Linde #1 HT ( High Test ), and Linde Planeweld (which in later years became one of the first Tig fillers to be used in the aviation industry).....pretty cool eh?

Cool