Streaky rust blue

[Roger B]

Used LMF to rust blue my barrel & it turned out pretty well except for one linear area next to the top flat.  This area developed during the process, so I sanded & degreased it & kept on going.  It looked like I had whipped it until I neutraized & was oiling, & there it was again!  I am tempted to use the Brownell's Express Blue (smells like Birchwood hot brown in use) to touch it up as I express blued some other parts for comparison, & it is a pretty close match.  What would you guys do; sand, degrease, & reapply LMF or try the express blue?  Asking because I thought someone else migh have had the same experience.
Roger B. 

[bdixon]

LMF should not really need degreased although I guess it would not hurt.  I know LMF does not like to be wiped on, meaning, rubbing the part with the rag or however you are applying it.  Just one swipe making it moist and no more.  Perhaps an anomaly in your metal???

[Roger B]

Could be the metal.  I've seen that before. 
Roger B.

[kutter]

I'd try a coat or two of express blue (hot rust blue) over the top of what you have.
Polish the area out a little and blend it in with the adjacent flats.
I've used hot rust over cold rust many times. There's really no problem in doing that.

As already pointed out, when applying Laurel Mtn, I've found that if I use anything but light pressure on the bit of dampened flannel that I'm using to coat the part with,,or use a back-and forth motion in one area, it'll leave a flash of copper coating on the metal. Must have some copper sulfate in the soln. Those areas will not blue the same as the rest.
If the metal is warm to the touch, the copper will easily flash coat out onto it when trying to apply the soln also and leave a spot in the final finish.
Sometimes the final results will look OK till close examination in sunlight shows it up.

Too much soln applied to the surface, especially on the first or second coating can cause a streak that'll show in the final results too.
No runny, wet areas of soln on the surface that take time to dry. Just the thinnest coating possible. Don't be tempted to go over areas that you have already covered to 'make them better' or maybe catch a sliver of metal that you missed. You'll get that on the next coating(s).

[Roger B]

Thinking back, I used to much pressure in applying the LMF & got it on too thick.  That explains why it didn't blue well at the breech end where some of the LMF accumulated.  I'm used to using Wahkon Bay brown which is completely unfinicky.  No problem though, because the express blue patches perfectly.  That's a really good thing because my dad dropped the barrel last night & scratched it severely .  Just another fix in a long line of fixes.  I really appreciate the advice guys.
Roger B.