Double Flaring tubing...

[Tigerstripe40]

Whats the trick?

I am making some brake lines for my rear disc brake conversion, and keep messing up the flares.

The FIRST one I did last night flared perfectly.
I cut and reflared another tube about 6 times and messed it up. EIther the flare wouldn't work out properly, or it would flop to one side or another....


And I did all of these flares exactlty the same way as the first one.


What I am doing, is after cutting the tubing, I deburr it, and sand it so that the end is flush and flat.

Then I chamfer the edge of the tube with my grinder so I get a nice 45 on it. I dress this with a file and sand it flush and flat again.

Then I put it into the double flare tool, and I screw it up.


Any hints?

Thanks!

 

[Degnol]

Tiger, I only had one bad flare out of many I've done and it happened when I did the first squash. I have a good flare tool, but was not tightening in the right sequence. Tighten the wing nut closest to where you have the tubing then really tighten the one farthest from the tubing. You get a lot more leverage that way. If the tube slips on the first squash, you're fawked. I don't know that is your problem for sure, just kinda a guess. But the trick, at least for me, was to get the tubing held firmly in the clamp with the proper amount exposed then go-cat-go.
HTH

Ed

 

[AZkick-n40]

When I screwed up - I just wasn't cinching it down hard enough on the first flare and kept splitting it. Tighten the ends like Degnol said and really torque down on the first flare.

HTH,

Brian

 

[Degnol]

I found it reall helpful to clamp the tool in a bench vise, you can gorilla it mo' betta'.

Ed

 

[dgangle]

Here's my solution. No need to flare. See posts 7 & 12 in this thread:

https://forum.ih8mud.com/showthread.php?t=41272&highlight=swagelok


More links:

http://www.swagelok.com/search/find_partnumbers_results.aspx?PS=S-300-2&PG=0&RPR=5
http://www.swagelok.com/search/find_partnumbers_results.aspx?PS=S-300-6&PG=0&RPR=5

 

[e rock]

Then I chamfer the edge of the tube with my grinder so I get a nice 45 on it. I dress this with a file and sand it flush and flat again.

Why chamfer the edge?

I just did about a dozen double flares while converting my 64 from stock single circuit drums to dual circuit disks. I messed up precisely 3. One was the first one, because I didn't mash it far enough on the first press. The other two were on the same piece because it was a lot harder tube. Most of the pieces I used were the new black "polymer coated" ones from Napa that are hand-bendable (I still used some bending pliers). They cut, bend and flare really easily and the parts guys said thay had heard nothing but good things about the new lines. The piece I had issue with was also from Napa, but it was a European metric piece (I bought it because I needed the fittings from it) that was harder steel - might be stainless??

Anyway, my process involved cutting with a tiny tubing cutter, knock the burr off the inside, mash, flare. That was all I did and they turned out great. This was my first time doing double flares and I thought it went really smoothly compared to others' first attempts. From the sounds of it, the tubing may be the difference.

 

[Tigerstripe40]

Why chamfer the edge?

I just did about a dozen double flares while converting my 64 from stock single circuit drums to dual circuit disks. I messed up precisely 3. One was the first one, because I didn't mash it far enough on the first press. The other two were on the same piece because it was a lot harder tube. Most of the pieces I used were the new black "polymer coated" ones from Napa that are hand-bendable (I still used some bending pliers). They cut, bend and flare really easily and the parts guys said thay had heard nothing but good things about the new lines. The piece I had issue with was also from Napa, but it was a European metric piece (I bought it because I needed the fittings from it) that was harder steel - might be stainless??

Anyway, my process involved cutting with a tiny tubing cutter, knock the burr off the inside, mash, flare. That was all I did and they turned out great. This was my first time doing double flares and I thought it went really smoothly compared to others' first attempts. From the sounds of it, the tubing may be the difference.

The Flaring Tool that I got (from Napa, BTW) says to chamfer the edge of the tubing before flaring.

That said, the practice flares I did before I started Chamfering came out more consistantly...

I will try just not chamfering and really cranking down on the flaring bar before.

IIRC stainless is actually softer than mild steel.

 

[bustanutley]

sounds like you are putting too much effort into it, just cut with a pipe cutter, then double flare, make sure you really pinch it in the tool and have the correct amount of material sticking out. Should be a 2-3 min operation total.

 

[bsevans]

Here's my solution. No need to flare. See posts 7 & 12 in this thread:

https://forum.ih8mud.com/showthread.php?t=41272&highlight=swagelok


More links:

http://www.swagelok.com/search/find_partnumbers_results.aspx?PS=S-300-2&PG=0&RPR=5
http://www.swagelok.com/search/find_partnumbers_results.aspx?PS=S-300-6&PG=0&RPR=5

Swagelok fittings are among the best flare less fittings you can buy. When properly installed they can handle far more pressure than they will ever see in a brake line. Having said that, they are illegal to use for brake line fittings on vehicles that will be driven on state and federal roads. They can be used on trailered vehicles that only see the trail head. If you run them on your street vehicle and have an accident - the liability issues could be expensive. Don’t get me wrong, my 20+ years experience using them leaves me with high confidence in their capability as long as you do not over tighten them. They make a gauge to show you when they are properly tightened. Do I think they would work as brake line fittings – absolutely. Are they DOT legal – absolutely not.

 

[dieselcruiserhead]

sounds like you are putting too much effort into it, just cut with a pipe cutter, then double flare, make sure you really pinch it in the tool and have the correct amount of material sticking out. Should be a 2-3 min operation total.

basically what I was thinking too.. I don't put much effort into it at all and have never had one fail...? If it is a little crooked it will probably leak but you will know instantly.. Also the second flair doesn't need to be super deep, it can be very mild and tightening the nut itself will put the flair into the brake line..

 

[dgangle]

...they are illegal to use for brake line fittings on vehicles that will be driven on state and federal roads.

This is very interesting. I do not doubt what you are saying is true and it is possible that you know more about this than I do. That having been said, there are no safety inspections here. Are you saying that by using these and if I were involved in an accident that I could found liable because I am using these, even if they had nothing to do with the cause? If so what is your source?

In a state that has safety inspections, would seeing these in use cause it not to pass?

Hell, steel coils fall off trucks here in Birmingham monthly punching 10' square holes in the interstates and sometimes killing people. The enforcing body can't stop this, whoever they are. Who would enforce this Swaglok thing and why would these 'DOT police' for lack of a better term be concerned about my little vehicle that only sees 1200 mi/yr and stays within a 50 mile radius of home? There are only something like 200 state troopers employed in the whole state with 1-2 on duty at any one time per county. If they are the safety police then I have nothing to worry about because they can't even keep up with the wrecks, let alone give many speeding tickets and surely not crawl under my hotrod to scold me for using a gizmo they probably don't even know what it is that doesn't have DOT approval. I'm making fun of this but you can see my point. We're shadetree mechanics, not General Motors or Ford.


What about the MAF FDB conversion that is labeled as "for off road use only"? Does anyone actually use this only off-road or is this just a CYA statement by Al Colebank's lawyers putting the liability on someone else as getting the appropriate approval is probably an involved and expensive process. Steve-O, what is your take on this?

 

[Gumby]

Proper amount of stick out is very important. Most of the screwed up flares, and I've seen the kids make a LOT of screwed up flares, are due to not tightening the clamp enough. Once I realized that and made it a major point in how I teach it, I get a lot more successfull flares on the first try.

 

[Tigerstripe40]

Cool.
Thanks for the pointers.

This truck is NOT a trailer Queen, and has to be safty inspected every year.
I will practice with the flaring tools some more, making sure to clamp down the flaring bar.

 

[bsevans]

Proper amount of stick out is very important. Most of the screwed up flares, and I've seen the kids make a LOT of screwed up flares, are due to not tightening the clamp enough. Once I realized that and made it a major point in how I teach it, I get a lot more successfull flares on the first try.

That is true. I think one of the problems is that a lot of double flare tools don't clamp the tube with enough force and the resultant slippage ends in unacceptable results. This is compounded when someone is trying to replace their brake lines with stainless steel brake lines.