Framebuildin' part 3


#4161

There is a sheet that lists a yield strength of 427 Mpa (62kpsi) which sounds fine, no idea about fatigue life. I imagine you’d have to silver braze.

The other concern is they only get ± 5% dimensional accuracy as there is some unpredictable shrinkage when they bake the bronze in, may have to run the parts twice to get the dimensions right.


#4162

Ah, like the Charge Ti dropouts.

Is there a way to make them stepped so you can use the bit that fits and either cut off or file/blend in the part you don’t use? Not optimal I know.

As far as fender attachments, I was contemplating messing about with rivnuts, but installing them so the longer portion is to the outside of the fender, then screwing into that from a simple tube boss. That would leave minimal protuberance inside the fender to catch crud. Also exploring PEMs but not sure if they have ones to work the way I want in M5 at how thin a typical fender is.

Or, why not use your current design, but bond them to the fender blade rather than screw or rivet?


#4163

EDIT: Nevermind!

Overall like a lot. Carry on.


#4164

Getting ready for Philly- who’s coming out?


#4165

Tell them to push it back a week and I’ll be there (for a conference).


#4166

i’ll be there


#4167

Ceramakote eric? How’d that work out? I look forward to the long term review


#4168

This


#4169

Did some practice. Started out having some problems getting full penetration especially in the crotch of the joint. Of course it turns out the answer was MORE HEAT WORK FASTER and I should just make a sign that says that and hang it on the cart.


#4170

That is the ugliest ashtray I have ever seen


#4171

I was thinking more sweet LARPing staff.


#4172

Yah, looks like a sword of many-hilts. +2 to parry.


#4173

can report it makes a cool whoosh sound when you swing it around. i dub thee “core sampler”


#4174

LOL


#4175

Tell me about using silver rod and a mapp torch to attach canti bosses


#4176

Silver is usually discouraged for canti bosses, unless you’re talking the hardware store nickel-silver rods. Assuming MAPP gas has the same BTUs it used to, then you can brass or nickel-silver them on.


#4177

Got a torch two days ago. SOS TOKED. I got lots of n00b Qs.

My setup:
Oxy/Propane. Oxy concentrator. Uniweld 71 handle, victor 3-TEN tip.
Cycle designs LFB + paste flux

Homework: 4130 - 7/8 0.028 on 1.125 0.035
1+ hour warm soak/ no rubbing


Before soak

  1. the CD flux is suppose to soak off pretty easily. I’ve tried soaking in cold water overnight (lazy) or warm tap water for 1+ hours and there are always tough patches that don’t come off on its own. What am I doing wrong? Too little flux? Overheat?

  2. How do I know if I have overheated things? Pitting in the bronze? Flux turning matte black?

  3. How do you tack? The bronze doesn’t flow until the metal goes a bit brighter than the initial red color (bright orange? I’m colorblind). I see a lot of internet pics with a blob of bronze on pristine tubes. How’s that possible? Intense spot heating? I preheat the whole assembly and there is no way the tubes look like that by the time bronze is ready to flow on the surface.

On the other hand, David Kirk tacks like what others called tinning pass. I tried it and can get similar looking results . It only takes maybe 15 more seconds total to go all the way around comparing to preheat + tack opposite sides.

  1. How to apply flux? Is it important to keep the flux very clean? I spoon some out of the jar into a working cup, where it gets dirtier cuz I’m messy. Straight up it’s too thick to spread around. I tried adding some water but it gets runny and thin real quick.

#4178

That’s pretty good for your first run.

black shit = burnt flux = too hot
coppery colored edges = too hot
pits can be overheating but also can be impurities and other shit.

be careful comparing your technique to pros because many of them run gasfluxers which totally changes the game.


#4179

[quote=drwelby]That’s pretty good for your first run.

black shit = burnt flux = too hot
coppery colored edges = too hot
pits can be overheating but also can be impurities and other shit.

be careful comparing your technique to pros because many of them run gasfluxers which totally changes the game.[/quote]

Thanks man.

coppery colored edges = too hot <<< not too sure what this means, do you see it in the pic above? is it the little dots of splatter on the edges?

I did not clean up the tubes well for practice so I will look out for that later. I was trying to do the bare minimum necessary for things to wet out.

Can you elaborate a bit about the differences I would expect to see if someone uses gasfluxer?


#4180

Yeah, on your top tree piece between the burnt flux and fillet there’s a section where it looks like it’s wet out with a thin coat that’s a different color. If you’re red/green colorblind it might be harder to discern. But you can also see it in that tinning pic on the right side. It’s not the problem that burnt flux is

[quote=buffoon]
Can you elaborate a bit about the differences I would expect to see if someone uses gasfluxer?[/quote]

The flux tends to look way more consistent and it seems to help with fillets. Usually people with gasfluxers are pros so technique and experience are a part but I’ve seen firsthand people before/after upgrading and it definitely makes a difference.