I've read about this stuff a few times, but never really gathered any solid reviews on it. Some people said it was awesome... some said it was pointless. So while filling the argon bottle a few weeks ago, i saw a can sitting on the shelf and decided to give it a try for myself. It was $70 for the can, pretty expensive, but i was feeling adventurous.



The instructions say to mix with methanol alcohol, so i used a bottle of HEET (99.9% methanol, 0.1% rust inhibitor).




***note*** Methanol is pretty nasty stuff, and inhaling it (or even it's exhaust fumes) can mess you up pretty bad. A few tuning books i've read mentioned it can cause schizophrenia. So use caution while mixing it up with the solar flux and try to avoid breathing the fumes. You essentially paint this stuff on, so it's easy to keep the mix away from the weld table in an area with better ventilation.

The consistency of the mix doesn't really matter all that much. I mixed it somewhat thin so i could easily smear it on the inside of the pipes with a small foam brush. If it's too thick, it'll clump up. Also, as the mix sits while you weld, it will dry up a bit. But you can just add a lil bit more methanol to it and mix it up again. Supposed to last up to a day before you should throw it out. And it really doesn't take a lot, i could have done this whole down pipe with only like two spoon fulls i bet (maybe even less).

Here's the test section i welded up. I was pretty damn liberal with the heat, cause i wanted to see if this stuff worked as advertised:





Normally a weld like this would have resulted in tons of sugar on the inside (again, i gave it plenty of heat to test this stuff fully). But to my surprise... the solar flux actually worked amazingly well:







It was hard to get a good pic, so i took a couple videos:





Some other little notes... When doing butt welds on thin wall pipe sections (rather than welding meaty flanges to pipe), i noticed that the steel glows much redder. It may have simply been from me not being scared to give it more heat (i don't usually back gas down pipes, i'll just use the filler rod and my foot to control penetration, and so i'm typically pretty light on the pedal)... but it seemed a little different.

Also, the solar flux does indeed leave behind a black glassy surface. I haven't tried to scrape any of it off, cause i don't care if it's in there on an uncatted down pipe. But I don't think i'd ever use the stuff on an exhaust manifold, or anything feeding a turbine. Those are probably still best done with traditional methods. But for down pipes and thin wall steels & alloys, solar flux seems to be awesome in my book.

Just figured i'd share my $.02 on the stuff since i haven't really seen any solid reviews of it. If any of you guys have tips or cautions, i'd love to hear em before i go and build 4 more down pipes and find out after the fact that they won't work lol.

 

Great info!

 

Pretty cool.. Gives me some ideas

 

Finished that dp up last night, and it came out awesome. I'm 100% hooked on this stuff.

I prefer mixing it somewhat thin, so it brushes on easily without clumps. It doesn't take much of a layer at all to do the job, and you really only need 1/4" on either side of the weld. I'm convinced a single spoonful would be enough for almost 2 down pipes i bet.

Also, i was even able to use the same brush i used last time. All the old dried flux just fell right off. Same with the dish i used to mix it up, just flake out the old stuff, and put in some fresh stuff.

Next, I'm gonna experiment with cleaning off the inside of the welds a bit, and see if there isn't an easy way to remove the glass flake. If there is an easy / reliable method... then i might be willing to try an exh manifold for myself, just to see if it damages the turbo or anything.

 

I've been using this stuff for a few years and it works great. You just have to remember to use it before you start taking tubes in place! lol

 

got pics with glassy flux residue scraped off?

 

I have this too, but never used it. Might have to give it a shot.... Good info!

 

Haven't taken any pics yet, but i did brush a few test sections to see how easily it's removed. The non-glassy parts of the paste come right off, more as a powder (like dried mud). The glassy parts however were more stubborn, and i was never really able to get them completely off with a wire brush. There was still a slight glassy residue. I'll snap some pics next time i'm in the garage working on this stuff.

I also made a little wire brush snake contraption, i'll test that out and post pics if it works even half way decent. It'll come in handy for down pipes and stuff i bet.

Only other thing i want to experiment with is some chemical solvents to see if that helps with removal. Maybe soak the stuff in some e85 or something and see if it loosens up some.

And to be honest, with how little residual glassy stuff is left behind after just scrubbing alone, i think i'm going to try an exh manifold just for giggles. I really don't think it will ruin my turbine... but there's only one way to find out.

 

No real technical updates, other than i've taken the plunge with using this stuff on a manifold:








I'll post more pics as it progresses. I still haven't experimented much with different methods for removing the stuff. Brushing alone seems to do a good job of getting the loose dried stuff off (it almost turns into a powder, kinda like dried mud). I just bought a little nylon brush that's used to clean out dryer vents and stuff, should work fine. I'll also play around with using e85 and / or gas this week to see if it helps with the scrubbing.

Just figured i'd bump the thread.

 

All runners are tacked.






I coated each weld section with solar flux before tacking the els in place. All it takes is like a 1/4 swathe from the edge of the el on each piece. The flux will dry almost like a dried line of mud, and seems to stay put even over a couple days time (started the runners on sunday). I have a few els that i coated but didn't use, and the flux paste on the inside looks just fine (hasn't fallen off or anything).


I'll start finish welding tonight, and then playing around with various cleaning techniques. I'll also post up what i'm using to apply this stuff and maybe a short video showing how i do it.

 

I spent less than $70 to buy a t-fitting for my tank valve and another HTP flow meter. Back purging is not some incredibly expensive or difficult thing to do.
I could see using the solar flux on an exhaust or something with large, long tubes that would require a lot of argon. Seems pointless and dangerous for a manifold though.

 

My bottle costs $75 to fill... and the LWS is 45 minutes away from my house... so simply making the trek down there to get more argon is a huge pita. Hence the reason i'm looking into this as an alternative. And i'm not trying to sell this as a "good" alternative, instead i've offered just the opposite advice and have expressed the risk involved. That's why i'm trying it on my own car first.

Manifold should be on the car this weekend. There are a few other projects i'm tackling at the same time, but i hope to have the car running by sunday night, or at least early next week at the latest.

 

Manifold's done.






Here's a shot into the turbine flange showing the glassy surface from the solar flux. It looks a little rough, but i think most of that is the camera flash. It's surprisingly smooth on the inside and will flow very nice:




This week i'll clean it out, and i hope to have it on the car shorty there after. I have a fair bit of work to do on other stuff before i can bolt it all back together, but hopefully won't be too long.

Here's a shot of the solar flux setup i'm currently using:




I bought a lil squirt bottle from harbor freight along with a 20 pack of paint brushes (i'm still using the first brush). I use a little plastic lid to mix the stuff up in. The plastic lid makes a nice dish since it's flexible and easily dumps the old dried mix out by twisting it back and forth over a trash can.

Pretty simple, and i'm still amazed at how little of the solar flux is required for so much welding. A half spoon full goes a very very long way.

 

looks terrible. I will offer to get rid of it for you so you can start from scratch.

 

Haha, i hope you're being sarcastic...

But if you're not... i'll happily let you build me another (better) one Just lemme know when you can start!

 

my sarcasm must be weak.... But you can still mail it to me, no questions asked

 

Lol, you never know. There are some fantastic welders on this site... so while i might take a bit of pride in this manifold, i have no doubt there are some on here who wouldn't touch it with a 10' pole.

I'll try to get it cleaned up tonight or tomorrow night and snap some shots of the inside.

 

Supposedly you should have the manifold sanded blasted out. You dont want those solar flux chips breaking off and going into a turbine. I remember someone raising a big stink about this years ago, but I don't remember if there was ever anything verifiable or if it was just opinion.

 

I think i found that old post when first researching the stuff, and as i remember you're right, there was no real solid proof. Just mostly opinion.

I've been driving my car all week, in and out of boost (10-12 psi), but no full wot. Have probably 200 miles on the car right now.






I didn't sand blast the inside, just hit it with a wire brush snake thing connected to a hand drill. Then i blew it out with compressed air.

I figure after a few heat cycles and some decent exhaust flow, any chunks and flakes should have come out by now. I've kept the boost relatively low to avoid very high turbine speeds, just in case. I'll probably put another hundred miles or so on it before i start going full wot.

I'm also buying an EFR 8374 soon So my fingers will be really crossed at that point. It's one thing to lose a "run of the mill" 35r, and a completely different thing to lose a hard to get EFR.

 

What kind of car is that?

 

A mazdaspeed 6.


I'm building a rotated up pipe for a friend's subaru today and got a few more solar flux pics.

Sched 10 still, here's a pic of the welds:



And here's the flux on the inside:




These small bumps would have been sugar city without the solar flux or back-purging:



But you can tell they're relatively smooth (picture makes them still look somewhat rough, but it's very minor when you run your finger over them):

 

that without back purging it? and how does it comes off after welding?

 

I used this flux alot at work, (not on X-ray pipe) I personally don't like it, because use of the silica that comes out. I prefer back purg.

 

Correct, no back purging, just experimenting with this solar flux paste. I scrub the insides of the pipe out with a snake after welding, and it cleans up decent. The glassy spots don't come off unless you really scrub the hell out of it with a wire brush... which isn't possibly on 95% of the exh manifolds out there. Right now i'm testing an exh mani to see if there are any issues with a flake or two coming off and going through the turbo, or any issues with weak welds. So far so good on my car.

When you say the "silica comes out", what exactly do you mean? And are you concerned with the weld integrity or contamination of the metal? Do you have first hand experience in whether or not the weld would be weakened by contamination? Most things i've read about silicon in steels is that in small percentages (~3%), it can actually increase the strength and heat resistance.

I'd love to hear some first hand experience if you have any. It's hard to find any solid info on this stuff honestly.

 

have you tried to sandblast it?