Mountain Project Logo

Best paint for SS hangers/ anchors?


M Hanna · · Seattle, WA · Joined Apr 2015 · Points: 5

I was recently reading an article about Duplex, which Fixe appears to be using a lot of these days.

https://www.bssa.org.uk/topics.php?article=668&featured=1

Probably don't want to try this color tint with Duplex hangers as they have a 300 C threshold, much lower than 316 or 304 if I'm reading that correctly.

Another BSSA article on heat tinting of stainless:

https://www.bssa.org.uk/topics.php?article=140

Jim Titt · · Germany · Joined Nov 2009 · Points: 490

Sigma-phase embrittlement is unlikely to be an issue with someone using a torch to color their hangers!

Taylor Krosbakken · · Duluth, MN · Joined Nov 2008 · Points: 446
Chris Vinson wrote: We leave them in a tumbler a couple days longer and it dulls them down significantly.  No heat treating, smoother edges etc..  just leave a note in the comments and we'll do it at no extra charge.

Neat! Can you do this with wave bolts?

Dan Frazer · · Unknown Hometown · Joined Apr 2017 · Points: 40

It sounds like heating is the way to go with ss hangers. Do you want to heat the hangers until they turn red or just wave the torch over them for a minute or so and call it good? 

Jim Titt · · Germany · Joined Nov 2009 · Points: 490

To get a hanger red is going to take ages with a torch (and it will be black afterwards), you just play the flame over trying to heat it evenly until it has the tint you want, maybe a minute or so.

Dan Frazer · · Unknown Hometown · Joined Apr 2017 · Points: 40

Thank you very much for the info

Chris Vinson · · Unknown Hometown · Joined May 2009 · Points: 0
Taylor Krosbakken wrote:

Neat! Can you do this with wave bolts?

Yep.

C. Williams · · the Climber Cave · Joined Jul 2013 · Points: 1,258

Here's what the twist bolts look like after about 30 seconds with a propane torch. The bottom bolt is for reference and was not heated.

Ma Ja · · Red River Gorge · Joined Sep 2017 · Points: 116

Just to be clear, torching a glue-in that is already set in place would be a terrible idea becasue of the heat transfer to the epoxy, right? Im assuming there's no way to retro recolor an existing glue-in?

kenr · · Unknown Hometown · Joined Oct 2010 · Points: 15,897

I'm not getting why it's important to change the color or reflectivity of Stainless steel glue-ins (before installation).

The reason lots of developers want to reduce the reflectivity of wedge or sleeve bolts with hangers is because the _hanger_ has a significant flat surface area which generates a bright "glint" reflection with the sun and an observer at just the right angle from each other. Key is that the surface is _flat_ so it reflects a significant total amount of photons from the sun in exactly the same direction.

. . . Such visible "glint" is even more of a problem with a Plated Steel hanger, because plated / galvanized steel tends to have much higher reflectivity than Stainless. My suspicion with a hanger that generates noticeable "glint" from a substantial distance is that it's likely Plated Steel - (a problem which might be solved in a different way).

Glue-in lacks any significant size of _flat_ surface area, therefore reducing its reflectivity is not so important, since the reflected "glint" is not concentrated enough at a single specific angle to be visible at any significant distance.

The idea of altering the reflectivity or color of a glue-in already in place seems like way overkill.

Ken

Micah H · · Portland, OR · Joined Oct 2016 · Points: 0
Jim Titt wrote:

Blue on stainless is around 500+C and has no effect at all. We anneal it at over 1100C and weld at over 1500C, the normal service temp for 316 is  around 870C. The only hassle with heat tinting is it's too slow for us to do it. The color charts and temps are easy to find, search for stainless steel heat tint color charts.



I'd suggest a word of caution is warranted regarding sensitization.  The colors people are trying to achieve here (dull blue, dark grey, red) are formed around 900-1200F.  While the degree of sensitization is dependent on the amount of time spent in this range (both upon heating and cooling), any amount of time will be detrimental to 300 series SS ability to resist corrosion.

Also, a thicker oxide layer might initially make a component more resistant to corrosion, but once that oxide layer is damaged (scratched) the materials ability to reform the oxide layer has been diminished due to the heating (and lack of proper oxide removal afterwards).  

I'm not saying yergonnadie, but its something to consider.  If one was to flame color hangers for use around salt water I'd be more concerned.  If you feel like this is absolutely something you need to do I'd recommend quenching the hangers after heating.  No, doing so isn't going to make it hard and brittle.  300 series stainless doesn't form martensite unless it's already buggered.

Definitely, absolutely, do not try to flame color duplex hangers.  If you're in an environment where duplex hangers are warranted, this should not be considered.  Unlike 300 SS, duplex will just get brittle and snap if heated and cooled improperly.  We could argue around on whether or not sigma phase could form during torch heating (it could), but why risk it?
Bobby Hutton · · Gold Country CA · Joined Aug 2013 · Points: 839
kenr wrote: I'm not getting why it's important to change the color or reflectivity of Stainless steel glue-ins (before installation).

The reason lots of developers want to reduce the reflectivity of wedge or sleeve bolts with hangers is because the _hanger_ has a significant flat surface area which generates a bright "glint" reflection with the sun and an observer at just the right angle from each other. Key is that the surface is _flat_ so it reflects a significant total amount of photons from the sun in exactly the same direction.

. . . Such visible "glint" is even more of a problem with a Plated Steel hanger, because plated / galvanized steel tends to have much higher reflectivity than Stainless. My suspicion with a hanger that generates noticeable "glint" from a substantial distance is that it's likely Plated Steel - (a problem which might be solved in a different way).

Glue-in lacks any significant size of _flat_ surface area, therefore reducing its reflectivity is not so important, since the reflected "glint" is not concentrated enough at a single specific angle to be visible at any significant distance.

The idea of altering the reflectivity or color of a glue-in already in place seems like way overkill.

Ken

I think I am coming around to the same conclusion. If I got my glue ins to the color that C. Williams achieved they would be so camouflaged it would be almost impossible to find them when leading. 

mattm · · TX · Joined Jun 2006 · Points: 1,381
Bobby Hutton wrote:

I think I am coming around to the same conclusion. If I got my glue ins to the color that C. Williams achieved they would be so camouflaged it would be almost impossible to find them when leading. 

I’ve had trouble spotting ones I PUT IN numerous times on limestone. 

Jim Titt · · Germany · Joined Nov 2009 · Points: 490
Micah H wrote:

I'd suggest a word of caution is warranted regarding sensitization.  The colors people are trying to achieve here (dull blue, dark grey, red) are formed around 900-1200F.  While the degree of sensitization is dependent on the amount of time spent in this range (both upon heating and cooling), any amount of time will be detrimental to 300 series SS ability to resist corrosion.

Also, a thicker oxide layer might initially make a component more resistant to corrosion, but once that oxide layer is damaged (scratched) the materials ability to reform the oxide layer has been diminished due to the heating (and lack of proper oxide removal afterwards).  

I'm not saying yergonnadie, but its something to consider.  If one was to flame color hangers for use around salt water I'd be more concerned.  If you feel like this is absolutely something you need to do I'd recommend quenching the hangers after heating.  No, doing so isn't going to make it hard and brittle.  300 series stainless doesn't form martensite unless it's already buggered.

Definitely, absolutely, do not try to flame color duplex hangers.  If you're in an environment where duplex hangers are warranted, this should not be considered.  Unlike 300 SS, duplex will just get brittle and snap if heated and cooled improperly.  We could argue around on whether or not sigma phase could form during torch heating (it could), but why risk it?

Hmm, sensitization isn´t going to occur either at the temperatures we are working with (unless people are actually making the stainless completely black) or at the time scales we are talking about, with the usual low-carbon alloys we are using it isn´t even a concern with normal welding so warming a bolt with a gas torch is doing nothing to form carbides.

Quenching does nothing.

The chromium layer under the heat tint is depleted but that is a six of one aand half a dozen of the other situation. The thicker layer of the tint provides more protection until it doesn´t then the depleted layer provides less. Both are more better than any coating method (apart possibly from plasma coating) so IF coloring the bolts is absolutely essential then I would prefer to see a tinted bolt/hanger. ANY post-treatment of stainless to remove the shine is detrimental to the corrosion resistance so it is a question of how much loss of protection is acceptable to obtain a usable bolt. Coloring bolts is a last resort where the alternative is no bolts are permitted, not something to do because someone likes doing it.

The sigma phase in 2205 duplex occurs between 1300 and 1800°F so double that of the heat tint temperature, in the sizes of material we are talking about normal air cooling will bring the material back to the desirable duplex condition anyway.  Precipitation takes hours (tens or hundreds) also at temperatures far higher than required for the colours we are talking about. Since the only commercially available duplex hangers go brown and rusty anyway it´s probably unescessary to try to camo them anyway  
Micah H · · Portland, OR · Joined Oct 2016 · Points: 0
Jim Titt wrote:

Hmm, sensitization isn´t going to occur either at the temperatures we are working with (unless people are actually making the stainless completely black) or at the time scales we are talking about, with the usual low-carbon alloys we are using it isn´t even a concern with normal welding so warming a bolt with a gas torch is doing nothing to form carbides.

Quenching does nothing.

The chromium layer under the heat tint is depleted but that is a six of one aand half a dozen of the other situation. The thicker layer of the tint provides more protection until it doesn´t then the depleted layer provides less. Both are more better than any coating method (apart possibly from plasma coating) so IF coloring the bolts is absolutely essential then I would prefer to see a tinted bolt/hanger. ANY post-treatment of stainless to remove the shine is detrimental to the corrosion resistance so it is a question of how much loss of protection is acceptable to obtain a usable bolt. Coloring bolts is a last resort where the alternative is no bolts are permitted, not something to do because someone likes doing it.

The sigma phase in 2205 duplex occurs between 1300 and 1800°F so double that of the heat tint temperature, in the sizes of material we are talking about normal air cooling will bring the material back to the desirable duplex condition anyway.  Precipitation takes hours (tens or hundreds) also at temperatures far higher than required for the colours we are talking about. Since the only commercially available duplex hangers go brown and rusty anyway it´s probably unescessary to try to camo them anyway  

We're going to have to agree to disagree.  I'm not saying 300SS hangers are going to corrode and fall apart in a year, but doing this WILL increase the chances of a crack forming, albeit we disagree over the percentage of that chance.

Precipitation of sigma phase takes significantly less than hours, and I've got a pile of failed test samples on my desk to prove it.  And if you think Jerry in the garage with a torch isn't capable of severely overheating a small hanger with a big torch (repeatedly) while trying to get the color just right, you haven't seen the monkeys I work with.  

Regarding the duplex hangers I look at it this way.  Could it be caused by a torch?  Absolutely.  Is it likely to happen?  Maybe not.  If it happens, will it eventually fail?  Absolutely.

If someone wants to send me a duplex hanger or two I'd be willing to try and test this out.
Jim Titt · · Germany · Joined Nov 2009 · Points: 490

I weld a lot of duplex (and 300 series) and workpiece cooling is standard for normal sections and welding speeds, over ca 50mm thick things change but I don't work with over 20mm. For 2205 (Outukumpu Code Plus Two) the sigma phase at 1200F occurs after 40 hours and it's highly unlikely anyone is going to heat that high for that long and even if they did a hanger would cool through the sigma phase anyway.

Guideline #1: Don't be a jerk.

Fixed Hardware: Bolts & Anchors
Post a Reply to "Best paint for SS hangers/ anchors?"

Log In to Reply