removing rusted / broken bolts

[grumpyvette]

READ THIS THREAD
a few facts!
ALL of us eventually find were forced to deal with a broken stud or bolt,or sensor that breaks off in the block or heads,it helps a great deal to lower your chances of busting off or stripping a bolt by soaking it in penetrating oil and heating and rapidly cooling it in repeated cycles at the first indication a bolt or studs stuck rather than trying to force it, what your trying to free up, and remove and replace it, hopefully without needing to repair the threads, and its location will determine to a great extent the method youll use to deal with that problem.matter, as to the method to be used in freeing up the bolt threads, and the tools, lubricants or process youll find useful, yeah! we ALL screw up! but with experience you learn some restraint and you learn to take your time!
IN MOST CASES SOAKING WITH A GOOD PENETRATING & LUBRICATING SPRAY< AND SOME REPEATED HEATING AND FREEZING CYCLES, WITH A TORCH AND FREEZE SPRAY, and REPEATED SPRAY OF THAT PENETRATING OIL WILL FREE UP THE THREADS ON THE BROKEN PART, ENOUGH FOR AN EXTRACTOR BIT TO SPIN IT OUT IF PROPERLY USED
EXAMPLE
small bolts like brake bleeder valves on brake calipers, heating the area with a propane torch and rapidly cooling metal with a freeze spray rapidly , cycling the temps tends to have the metal expand and contract, loosening the bond in the rusted or corroded threads, because they expand and contract unevenly, this can be very useful in allowing you to soak in and use various penetrating lubricants to free up jammed threads
BUSTED OR STRIPPED THREADS CAN BE REPAIRED THRU USE OF A HELICOIL OR WELDING AND DRILLING & RE-TAPPING
http://www.mcmaster.com/#thread-repair-kits/=wjqvpt

viewtopic.php?f=27&t=1262&p=2712&hilit=taps+dies#p2712

viewtopic.php?f=27&t=4714&p=18266#p18266
yeah, IF I was your local machine shop Id welcome these type of repair jobs, I'd be thrilled to make a quick $30-$40 for what might take them 15 minutes to do and cost them less than $4 TOO!
having access to the correct tools and the skill and knowledge to use them correctly makes a job the average guy finds rather challenging a whole lot less difficult
WATCH VIDEOS, YOULL LEARN A GOOD DEAL
https://www.youtube.com/watch?v=m4e5d-QeRjI

https://www.youtube.com/watch?v=46bIm2xaLuc

https://www.youtube.com/watch?v=0iyJtGNemq4

https://www.youtube.com/watch?v=mRGcuGK-POs

https://www.youtube.com/watch?v=e6bb-SSRn6c

https://www.youtube.com/watch?v=52-37pPAJ0c

https://www.youtube.com/watch?v=K34RS6M11uw

http://www.harborfreight.com/45-Pc-Tita ... 61411.html








stop think it thru ,yes its going to be a whole lot cheaper to buy and use the correct spray, penetrating oil or freeze spray to freeze and contract the bolts diam. or heat the surrounding metal and rapidly cool it with penetrating oil than it will be to use tools than it will be sometimes used incorrectly to bugger up, and strip the bolt hole, or bolt threads and need to re-weld and re-drill and tap the intake, brakes or what ever your working on, after you screw it up, buy the two sprays, both the freeze and lubricant sprays use the torch to heat the bolt, use the penetrate oil to cool and lube the bolt, use the freeze to loosen it easily

reverse twist drill bits can be useful
http://www.northerntool.com/shop/tools/ ... 7AodjQIAhw
(1)heating the brake fluid bleed fitting cherry red destroys the metals temper and hardness and makes it very easy to round off or sheer off the fitting (neither being ideal)

(2)the object is to loosen or replace the fitting without damage to the brakes, yes heating with a torch and rapid cooling with penetrating oil can and does frequently result in loosening the fitting but heating more than about 300F reduces the metals strength and frequently results in compounding the problem when the bleed valve fitting rounds off or breaks

heres the cure on those bleed valves
heat the area slightly spray oil to cool and penetrate then lay a shop rag on the brake calipers to cover all but the bleed fitting and spray with the freeze spray, the result is the fitting contracts faster than the surrounding metal freeing the threads in most cases on the first or second application of this COMBINED PROCESS of heat,penetrating oil, and rapid freezing of the valve rapidly followed by use of a long 6 point box wrench applying torque to the fitting, (BTW( a couple whacks with a plastic mallet can help in some cases

http://loctitefreezeandrelease.com/

lets assume youve busted an exhaust manifold bolt
these have been repeatedly heated and cooled so heating and spraying with a good penetrating oil is a good first try, use of the freeze spray can be very helpful IF you can grasp the bolt above the surface its screwed into,but if it sheared off flush you have little choice but to heat, use penetrating oil, and then use a center punch to dimple the broken bolt body, and drill it out the center of the bolt with drills that are slightly smaller diam (hopefully all the way thru, spray penetrating oil so it reaches both ends of the threads and use an EASY-OUT reverse rotation bit to extract the remaining section of busted bolt thread.
READ THE LINKED INFO
viewtopic.php?f=50&t=729&p=1026&hilit=easyout#p1026

http://www.madelectrical.com/workshop/b ... olts.shtml

WELDING A NUT ON A BOLT THATS SHEARED OFF WORKS AT TIMES
https://www.youtube.com/watch?v=aRrz-cphBY4

http://www.weldingtipsandtricks.com/rem ... -bolt.html

http://www.bing.com/videos/search?q=wel ... 9C64EDFC2D

https://www.youtube.com/watch?v=g6w2grAV-oc

https://www.youtube.com/watch?v=4BFUfGKU_ts

viewtopic.php?f=27&t=3283&p=8681&hilit=label#p8681


spray busted stud or bolt threads with penetrating oil




AT TIME I KNOW YOU GUYS HAD TO IGNORE READING THE LINKS

[b]youll frequently have issues with locations that make it difficult to hold the washer or nut centered over the busted stud while getting ready to weld due to either clearance or lack of having 3 hands available, most of the non-WELDERS MIGHT SUGGEST MAGNETS ,but as most welders soon learn direct heat or an electrical arc kills magnets rapidly, DUCT tape tends to hold long enough to allow the MIG OR TIG welder to form a BEAD but it will of course burn in seconds. many times you can use a spare TIG welding rod bent into a long hook to some higher support point and wrapped around the nut plus duct tape or a long wood dowel wedged in place to get that temporary placement issue handled
find a matching washer and nut , placing a fender washer as a shield washer under the nut your welding to the busted bolt or stud helps prevent weld from attaching to anything but the threaded shaft, and the heat drives the penetrating oil into the threads, duct tape and or long needle nose plies come in handy holding it in place and a MIG or TIG welder is preferred

fill the nut with weld and get the weld pool of molten metal to attach to the busted stud so concentrate on the center heat area

removed busted stud or bolt with nut welded on









in an ideal world youll have a decent center punch


http://www.google.com/imgres?imgurl=htt ... 4&ct=image
so the drill won,t wander, off center in the first bit of drilling the hole for the bolt extractor, soak with penetrating oil, insert extractor bit , inside the drilled hole and spin the bolt out as it grabs the bolt internally and allows you to rotate it counter clock wise

http://www.youtube.com/watch?v=A7ftJTUbp4o

http://www.brokentap.com/easy-outs.html

http://www.ehow.com/how_5127433_use-easy-outs.html


RELATED THREADS
viewtopic.php?f=59&t=1264&p=6141&hilit=block+taps+threads#p6141

viewtopic.php?f=50&t=729&p=1026&hilit=+rust+bolt+extractor#p1026

those freeze sprays seem to work best when you previously cycle or rapidly repeat an expansion contraction cycle several times, pre-heat the problem threads several times with a propane torch to about 250 degrees F and cool them off with a 50%/50% mix of marvel mystery oil and acetone then let the freeze spray free it up on about the third or forth heat-lube-cool freeze in rapid succession, that maximizes the expansion & contraction and tends to allow the penetrating lube to suck into the threads
one more place a IR temp gun comes in handy

http://www.professionalequipment.com/xq/ASP/ProductID.3461/id.22/subID.177/qx/default.htm

when selecting an IR gun for automotive use, you really want to be able to read from 0 F deg-about 1400F deg. to cover most conditions you'll test for


keep some penertating oil/acetone, mix a torch, and freeze spray plus the IR temp gun, in the shop


viewtopic.php?f=50&t=729&p=1026&hilit=easyout#p1026

http://www.freealloil.com/

http://www.crustyquinns.com/tech/easyout.html

http://www.asashop.org/autoinc/may2003/techtotech.cfm

if you can drill thru the center of the broken bolt with a bit approximately 2/3 the diam. of the broken bolt, until the bit goes ALL the way thru then soak the $%^ out of it with FREEALL penetrating oil,(this stuffs amazing) this will allow the oil to soak in from both ends of the broken threaded section, let it soak at least 30 minute while you re-apply more spray oil every few minutes, then insert the easy out or reverse twist drill bit,and gently twist the broken bolt remains out of the threaded hole, BTW heating and cooling the bolt, helps. heat with a propane torch the cooling it with the spray oil helps to loosen its grip on the threads if its really stuck

http://www.jackstoolshed.com/index/page ... ll+Bit+Set

your local hard ware store probably has COBALT DRILL BITS, or DIAMOND DRILL BITS, but read the label you need, a bit rated for hard steel, take your time, drill a lower RPM speeds and keep the bit wet with spray oil AT ALL TIMES or it will burn and dull the edge, youll most likely need a 1/8" and a matching EASY OUT

http://www.diyfaq.org.uk/powertools/drillfaq.htm

http://www.askthebuilder.com/How_To_Dri ... ideo.shtml


http://www.toolprice.com/category/screw ... drillbits/

http://www.toolprice.com/product/1218A/ ... moval.html

http://www.toolprice.com/product/8304D/ ... o_USA.html




Some of you might appreciate this. Machinist's Workshop magazine
tested penetrants for break out torque on rusted nuts.
They are below, as forwarded by an ex-student and professional
machinist, Bud Baker.
They arranged a subjective test of all the popular penetrants
with the control being the torque required to remove the nut from
a "scientifically rusted" environment.
*Penetrating oil ..... Average load*
None ...................... 516 pounds
WD-40 ..................... 238 pounds
PB Blaster ................ 214 pounds
Liquid Wrench ............. 127 pounds
Kano Kroil ................ 106 pounds
ATF-Acetone mix..............53 pounds

The ATF-Acetone mix was a "home brew" mix of 50 - 50 automatic
transmission fluid and acetone,
( IN MY EXPERIENCE MARVEL MYSTERY OIL AND ACETONE MIXED 50%/50% works slightly better and faster).
Note the "home brew" was better
than any commercial product in this one particular test.AND ID POINT OUT THAT MMO/ACETONE MIX PENETRATES QUICKLY AND SEEMS TO WORK WHERE MANY OTHER PENETRATING OIL FAILS




IF youve ever rounded off a flare nut, on a master cylinder, brake caliper,transmission or radiator and you want to prevent it from happening again, theres a simple procedure for getting them loose that works about 90% of the time
IN THE FUTURE WHEN DEALING WITH FLARE NUTS, IF THEY ARE NOT EASILY TURNED, STOP AND FOLLOW THIS PROCEDURE

(1) spray with a good penetrating oil,
(3) spray with OR A GOOD PENETRATING OIL like pb blaster / liquid wrench, freealloil etc. and tap frequently and lightly with a hammer on the broken stud or bolt to allow vibration to let the penetrating oil seep into the threads if it can,
http://www.freealloil.com/

(2) heat briefly with propane torch



(3) spray with


http://www.freealloil.com/ OR A GOOD PENETRATING OIL like pb blaster / liquid wrench,\l etc.

(4) wait 5 minutes MINIMUM and RE-SPRAY with
http://www.freealloil.com/ OR A GOOD PENETRATING OIL like pb blaster / liquid wrench, etc.


(5)spray for a minimum of 5-6 seconds with
http://www.loctitefreezeandrelease.com/


http://www.amazon.com/Loctite-Freeze-Re ... B001VXU474

and immediately


(6) USE THE CORRECT WRENCH

http://www.csnstores.com/asp/show_detai ... ku=IHI1184




before RE-INSTALLING COAT THE THREADS WITH ANTI-SEIZE PASTE, as it tends to prevent future problems



yes you can most likely get the bolt out by tapping it and the use of lubricant spray or heating and cooling or just the freeze spray but your taking a significant chance of the stud not being nearly as easy to remove, its your choice naturally but in the long run doing things correctly using all the steps in order will save you a good deal of time and money.
the lube, heat,lube,freeze in rapid succession, then the gentle but consistent twist torque of the easy out in the drilled centered hole in the broken bolt or vise grip applied to a bolt or stud thats sticking above the surface enough to grip will remove most studs or bolts, installing the studs or bolts with ANTI-SEIZE on the threads prevents this from occurring

READ THE LINK
viewtopic.php?f=50&t=729&p=1026&hilit=easyout#p1026
obviously I'm not there, to help out, but repeated heat, lubricate, freeze and lube application cycles WILL allow the threads to be broken loose from the corrosion, in the threads holding the stud or bolt, its simply a mater of repeated expansion and contraction of the two metals and the difference in heat transfer between the two parts, most new guys get into a hurry, thinking they can do it once or force it, , and don,t use enough heat or lube spray or freeze spray and try to force it rather than allow the repeated cycling to allow the lubricant to seep into the threads.
yes it usually helps to drill a small centered hole thru the bolt so lubricant spray can act or seep in from both ends of the threads, but forcing it usually results in the broken extractor bit you experienced, your surely not the first or the last guy to do that its part of the learning curve.
if the bolt can,t be grasp with vise grips youll need to center punch then carefully drill the busted section of bolt or stud., DON.T by cheap imported screw extractors the cheap extractors tend to be hardened excessively and BRITTLE, take your time, is it won,t back out keep repeating the heat.lube and freeze cycles, it will come out, there are reverse twist drill bits that can also tend to make the process far easier in many cases, and remember use of quality drill bits and a drill press usually gets far more consistent results than a hand held drill thats rarely going to be strait or centered.
cheap drill bits drill bit extractors or rushing the process invites failure
high drill speed or cutting without lubricant or excessive pressure only causes the drill bit to burn, dull or wander take your time and do whats required slowly and carefully with quality drills and taps or extractors ,if you can,t slow down,and do whats required or don,t have the correct, tools take it to a good local machine shop.

viewtopic.php?f=27&t=4714&p=12809&hilit=drill+bits#p12809

viewtopic.php?f=27&t=970&p=1691&hilit=drill+bits#p1691

viewtopic.php?f=50&t=7132&p=23959#p23959

http://www.crustyquinns.com/tech/easyout.html

HERES A DIFFERENT OPTION

http://www.theinductor.com/


http://www.jegs.com/i/JEGS/555/W88030/1 ... 7AodeF8Ajg

on rare occasions you'll have a nut rusted too a stud that needs to be split off and the stud re-threaded or replaced

[Big_John]

I've used left handed drills many times with good success. Every situation calls for different solutions. Heat from an oxyactelene torch works a bit better then a propane or map gas torch.

I've even blown the center out of larger bolts with a cutting torch... If you do it right, the bolt is gone and the threads are still good. Its not for the faint of heart though.

I've had pretty good luck using PB Blaster penetrating oil too.

viewtopic.php?f=50&t=2204
a good example, of a snapped off bolt in need of removal

[grumpyvette]

OK lets say you've screwed up and busted off a EASY-OUT hardened steel bit during the bolt removal process, now what?
obviously you'll quickly find out that standard drill bits won,t touch a l EASY-OUT hardened steel bit style bit as its far harder than most standard drill bits

you should know that hardened steel requires a slow drill speed (UNDER 300rpm in most cases) AND REQUIREs a constant flow of cooling oil, or a hardened drill bit will very quickly loose its edge, in seconds in some cases, YES IM WELL AWARE,that the tendency is to lean on the drill bit and spin it as fast as you can, which is exactly the wrong approach here, you need to apply steady pressure and low drill speeds and frequent lubrication, Ive used marvel mystery oil mixed with about 30% acetone as a lubricant for years with good results, but its very important to lube frequently,and drill slowly WD40 works as does CRC spray lube.
a hardened center punch helps center the bit and keep it from wandering off center.

http://www.ehow.com/video_4950955_drill ... steel.html

http://www.youtube.com/watch?v=D4q8UhbpaG0

When to Use a Carbide Drill Bit
By: Gene Rodriguez, III

Drill bits undergo a lot of stress when drilling a hole. The high-speed rotation of drill bits generates friction that, in turn, generates heat. The friction between drill bit and material leaves drill bits slightly duller after each use. The heating and cooling of the drill bit material can weaken the internal structure of the bit over time.

The Common Drill Bit
Common home repair drill bits are made of steel or High Speed Steel (HSS). Although inexpensive, common steel drill bits tend to wear out or break very quickly. HSS drill bits last longer than steel, but are more expensive. These types of drill bits are most effective when used on wood, drywall or plastics.

A Bit Stronger
Coated drill bits use another, harder material to coat steel or HSS drill bits. Titanium carbide or titanium nitride coatings can increase the lifespan of a drill bit by two to three times. These types of drill bits are useful when drilling hardwoods or thin metals.

When The Going Gets Tough
Carbide drill bits are among the strongest drill bits available for home use. Carbide drill bits are more expensive than steel or titanium coated drill bits, but will last longer and stay sharper.

Carbide drill bits are absolutely necessary when drilling stainless steel or other high-density materials. No other drill bit can handle the job.

Regardless of the material that you usually drill, a carbide drill bit will last up to 25 times longer than a common steel bit. This can make carbide drill bits an economical choice for woodworking, furniture building or other large-scale projects.

When cutting dense material, use a cutting lubricant to avoid generating excessive heat. Overheating a carbide drill bit will shorten its lifespan. Always let the drill bit do the work. Applying too much pressure will quickly dull your drill bit.

http://www.ncprogramming.com/drill_size_chart.html

http://www.thetoolhut.com/tap-drill-sizes.html

http://www.drillbitwarehouse.com/home?p ... egory_id=9


titanium drill bits, better than high speed steel but may not be hard enough

Carbide drill bits,very good but fairly expensive

diamond drill bits--best, very expensive

[grumpyvette]

BOBB was kind enough to post this tip
"Paul, I noticed in your post on removing broken bolts and such that you dont seem to use a welding machine much. i almost always use one. stick or mig depending on situation. there is a rod called an extractor rod or something like that for stick welders. most of the time i get a thick flatwasher with the plating removed. hold it down over the offending broken part, and hit it with a good hot tack, dead center. then keep hitting it with tacks till i can get the washer involved. then its a good hot burn dead center. then get a nut. hold it on there standing sideways, and weld that on. let cool and then wiggle it loose. i have done this dozens of times over the last 30+ years and its the way i do it almost all of the time, even on machine screws. you can even do it with the bolt broken 2-3 threads down in the hole if you have that anti burn welding putty. i don't share this method much but do with it as you wish. I like it on real old rusty stuff thats been broken off for years. the concentrated heat breaks the rust real well. try it Im sure you will like it."


BOBB,Ive done it, in the past,and your correct it works, great, but probably 8 out of 10 guys either don,t own a welder or don,t have the skill to use it correctly, this info is certainly useful and valid for the few that can use it

[mathd]

Ok, and now if you have an oil pan bolt, that was too long(because it was made for a aluminium oil pan wich is thicker) AND who also got overtorqued and broke( Yeah when i go stupid..).. I tryed drilling it out with reversed drill bit didnt work, i tryed easy out wich broke in it(it also grabbed the block since the easy out was oversize to the bolt hole"thats what happened after bending the 2 smaller one of the kit..."). Apparently i was never able to drill the easy-out with a carbon drill bit, i should have tryed slow speed and oil/cooling. But i feel like this one will never come out since it got stuck tappered too far in the block where there is no thread tapped.

I have no oil leak so far so ive kept it that way, but if an oil leak happen i will try the welder method otherwise i will have to change the block completly or find a competent shop(hard to find a shop that can do this job wher i live) to weld and drill/tap a new bolt hole.

[northrnyankee]

for this one I'd weld a nut to the stud..

[bobinda808]

i realize that not everyone has the means or ability to weld a nut on it. so its back to the drill. the drill that seems to always wander off the centerpunch. (its the magnetical force of the rotation of the planet that does this) no biggy, just steer the bit back to center by tilting it as much as needed. it like a gun, aim it where you want it to go. when it gets back to center aim it straight into and through the bolt. if you broke a tap off in the hole you will need a tap extractor or a welder cause drilling a tap or other such very hard metals like a carbide die grinder bit is near impossible.

[grumpyvette]

a drill press , used with a vise holding the part securely and use of quality drill bits used while taking it slow and easy with lots of cutting oil
will make this an easy process about 20%-40% of the time the other 60%-80% of the time is a TOTAL P.I.T.A. because you can,t for a dozen reasons get the defective part up on a drill press vise, but the quality of the drill bits and cutting oil and slow drill rpms still apply if you want to be successful..many, probably most guys find out that hand held drills and simply applying more pressure to the drill and rpms invariably results in burnt, dull ruined ,broken or bent drill bits that won,t remain centered in the broken stud or bolt

read linked info
viewtopic.php?f=27&t=4714&p=12809&hilit=drill+bits#p12809


and if you screw up and bust the drill or TAP?
http://www.waltontools.com/

http://www.waltontools.com/prod.htm

[Dustytrix]

I have heated bolts up or the area around the bolt, and then used wax to penetrate the threads, it works as good as oil. Just something different, for certain situations.

[grumpyvette]

Ive tried that also, and your correct in some cases it works just fine, but the best penetrating/lube oil Ive yet found hands down is

and a 50%/50% mix of marvel mystery oil and ACETONE is also really effective
Id try several repeated cycles of using a propane torch to heat the stud and rapid cooling with
http://loctitefreezeandrelease.com/
Ive always found that heating a stuck or busted bolt with an acetylene torch then dribbling a 50%/50% mix of marvel mystery oil on the bolt to cool it several times in repetition tends to allow the penetrating oil mix to penetrate, and now that theres
http://www.loctitefreezeandrelease.com/
following up with freeze spray works even better
OR



viewtopic.php?f=50&t=837&p=1264&hilit=taps#p1264
if it was not loose in a few minutes
Id try soaking it in a 50% / 50% mix of MARVEL MYSTERY OIL AND ACETONE AS A SOLVENT/PENETRATING OIL for a few hours then giving it a few whacks with a plastic hammer a few times while letting it soak over night then use the freeze spray, yes you might need to drill and easy out a real stubborn stud but you might be surprised at what time , persistence and repeated rapid extreme swings in heat cycles, expanding and rapid cooling with oil with penetrating oil will do, especially with the torch, lube and freeze spray

[grumpyvette]

I'll play along:D

While removing the body on my Vette one of the body mount bolts didn't have a head anymore. It had rusted to the point there wasn't any place for a wrench to grab to. My solution was to weld a nut to what was left on it. This is done best with a wire welder, easier to get to. Turn the welder up fairly hot and weld the center of the nut to the old bolt. The heat it generates also helps with the removal. While the bolt is still hot go ahead and remove it. If the nut breaks off try it again, sometimes you don't get a good weld the first time.

[87vette81big]

I will Try Your Acetone & Marvel Mystery Oil Trick Next time Grumpy.
Its working for You.
Marvel Mystery Oil is good stuff.
Been using it lately in all my vehicles.

[hcbph]

I have not seen MMO and acetone used before, but I have seen ATF and acetone used with superior results. I've seen some woodworking machinery that was left outside for decades and rusted up solid that a ATF/Acetone 50-50 mix was used on and fasteners were removed. Like anything else, it was not immediate but it worked.
Another one if it's steel and not alloy or pot metal parts, sometimes electrolysis can be used to get parts loose in addition to removing rust. It also does a good job of removing old paint. Again this has been used for years on old woodworking equipment being restored.

[grumpyvette]

I have not seen MMO and acetone used before, but I have seen ATF and acetone used with superior results. I've seen some woodworking machinery that was left outside for decades and rusted up solid that a ATF/Acetone 50-50 mix was used on and fasteners were removed. Like anything else, it was not immediate but it worked.
Another one if it's steel and not alloy or pot metal parts, sometimes electrolysis can be used to get parts loose in addition to removing rust. It also does a good job of removing old paint. Again this has been used for years on old woodworking equipment being restored.

yes thats a good point that most newer guys don,t seem to fully appreciate !
several repeated cycles of rapid heating,followed by rapid cooling breaks the corrosion surface bonds in rusted threads, by soaking it down with that 50%/50% acetone/ M.M.O.mix and allowing time to let the penetrating properties of that mixture, soak into the cracks and threads over several minutes after each cycle or expansion and contraction, this can usually be done in 3 too 5 cycles if a good deal of the penetrating lubricant is used, but in rare cases it could take hours or even days are at times ,are required for the threads to be fully penetrated and loosed on stubborn ,heavily rusted bolts and most guys want to rush and force it,taking your time will allow the bolt or stud to be removed in most cases with little damage to the main component, rushing the process can and frequently does cause expensive repair work so going back and soaking it repeatedly and in some cases placing a sopping/dripping wet piece of scrap rag soaked in the mix on top of the frozen bolt or nut tends to aid penetration, rushing it seldom produces the desired results, but having a bit of patience frequently pays off in far easier to repair parts, where trying to force it results in increased repair and replacement costs.
that fact can be critical on nearly impossible to find older parts, that will be hard to replace or repair if extensively damaged
ID also point out that coating the threads with a good quality ANTI-SEIZE paste before they were assembled will do a long way toward preventing it from re-occuring

RUST REMOVAL RELATED
viewtopic.php?f=71&t=9753&p=36702&hilit=electrolysis#p36702

viewtopic.php?f=51&t=2300&p=30653&hilit=electrolysis#p30653

viewtopic.php?f=57&t=74&p=93&hilit=electrolysis#p93

viewtopic.php?f=50&t=3224&p=19693&hilit=+rust+preventive+spray#p19693

viewtopic.php?f=61&t=5003&p=25222&hilit=rust+acid#p25222

[87vette81big]

One of the Worst a Modern Day Mechanic faces today is Broken Exhaust manifold studs on a Ford Triton 2-valve Engine on a 4.6, 5.4, 6.8LV10 in a F-150, F250 2wd or 4wd pickup or Ford Excursuon with 200,00-400,00 miles on the Odometer.
Working against the Flatrate Clock.
Job only pays 8-10 hours all together.
In this Economy you must do or starve & your family starves too.

Welding nuts only works
1/2 the time. Steel is fatigued & keeps snapping off.
Many snap off 1/4-1/2" below the surface.
Not uncommon to have 10-22 Broken off 8mm studs.
You don't want to remove both heads because its Chain driven SOHC.
Its a Real Mother F of a job to do.
Done at least 50 Broken exhaust manifold to cylinder head jobs in last 5 years.

Making your own Short Stubby 2-3" Drill bits is a must do.
Use a Snap On Right Angle Low profile Reversible Air Drill.
Only way to get in & drill.
Cut drill bits off with a cutoff wheel.
Use Straight shank part.
Resharpen on a bench grinder or Drill Doctor.
A few Solid Carbide Drill bits Twist flute style good to have also.

[87vette81big]

Don't use easy outs. They will snap off.
Then must remove Ford Heads & have Electron drilled out.
Been there done that.
Keep drilling.
Tap clean with 8mmX 1.25 Tap.

Good Luck.
Need it.
Real skill & patience required.