: rusty bolts removal tips

08-02-05, 03:21 PM
anyone have any good tips on how to get rusty bolts loose and out without breaking them? i am using p.b. blaster, but am hoping maybe some of you have something that can help me. give me anything, thank you.

terrible one
08-02-05, 07:57 PM
p.b. blaster worked for me after spraying them for 2 weeks. However, you will find that some of them will never get loose no matter what you do (or at least I did). I ended up with 4 that I just couldn't get after 3 weeks of spraying, and eventually torching. Anyways I ended up just snapping them on purpose, taking the manifold off, and then taking the heads to the machine shop to get bored and rethreaded.

If you don't feel like spending any money, i have been told that you can take a cutting torch to them and the steel will melt and the cast iron won't. Not too sure on that one though.

08-02-05, 08:15 PM
Sometimes the "blue tip wrench" (torch) works great if it is in an area that will allow it. Get that bolt red hot and then have at it.

08-02-05, 09:20 PM
My favorite chemical brew is Break Free; available at your local gun shop.

08-02-05, 10:21 PM
yeah, my friend told me today about getting the bolt red hot. i always thought that you heated up the block and not the bolt. maybe both work. thanks for the help

terrible one
08-04-05, 11:47 PM
I always went for the block, thinking of the law of heat making metal expand. I guess I was thinking the block would expand making the hole for the bolt a bit bigger.

Anyways this way worked alright for me and also lead to the discovery of the condition of my engine and the performance rebuild I am now doing.

08-05-05, 12:45 PM
I've found that not all rusted fateners can be treated to remove. When the two metal surfaces get corroded together in such a way heat is the only way to get them to release a bit in order for the penetrant to work it's way into interfering with the bond. Depending on how much time you have, access to the fastener, and so on, I'll heat two surfaces as equally as possible several times. Expansion/contraction IS MOVEMENT, that's what frees up corrosive welds. Just as the metal is cool enough to apply the penetrant I'll soak it, and then repeat as much as 4 or 5 times. I'll then test it first tightening it just to stress the surface tension and the loosen to see if it breaks free. This usually works.
Then there is the drilling method. Starting with the smallest bit I can and working up to as close to the minor diameter of the bolt/stud as I can. It weakens the structural part of the fastener. That's depending on all other factors too, location, time, tools and place, and so on.
And as some have mentioned, theres always the acceteline wrench, but if possible I'll grind the head off smooth, remove the unit being held in place, and then work on the remaining fastener to loosen it hopefully saving the internal threads. If it's a through bolt and access to both ends, blow that sucker off and punch it through.
If all else fails, Heli-Coils are cheap!

08-05-05, 10:30 PM
Sometimes the "blue tip wrench" (torch) works great if it is in an area that will allow it. Get that bolt red hot and then have at it.

This and rub some wax on the hot bolt works for me... I've even removed exhaust manifold bolts using this technique.

08-09-05, 12:28 PM
alright, thanks for the help

11-07-06, 06:02 PM
Get yourself a MAPP gas torch for $40 at Lowes...those burn hotter than propane which means you don't have to wait so long when heating things up. Just be careful/aware of what is around whatever bolt you're heating.

11-16-06, 01:08 PM
Heat the bolt with an acetylene torch until it's red hot. It expands but the bolt is restrained by the metal it is screwed into and collapses on itself. When the bolt cools it contracts and loosens. If you twist the head off anyway the answer is a TIG welder. If the bolt is broken off flush with the surface, build it up with the welder until you can weld a nut to it. When it cools put a wrench on it. If you twist it off again, weld a nut on it again. A rusty twisted off bolt is sometimes loosened by smacking it with a very sturdy punch and hammer to drive it down and make something happen inside. Twisted off manifold bolts can sometimes be removed by building up a lump of brass on the bloody stub and grabbing it with vice grips to twist it out. Which of these techniques you use as well as many others depends on the circumstances. I've been cleaning up other peoples messes for 50 years and have a pretty good reputation in the area. The absolute last resort is drilling and "easyouts". 90% of what can happen is bad.

12-21-06, 11:50 PM
3 tricks I use pretty much every week if not day. I (if area alllows) heat up the part that the bolt is going into NEVER HEAT A BOLT UNLESS ITS LAST RESORT, it will soften the bolt and guarantee it will twist off.
OK cheap trick in a pinch a 6 dollar propane torch, a parrafin stick(candle, gulf was cut up)get it hot and wipe some wax on it and let it wick into the threads and keep heating and wiping for a time then give it a shot.
Another trick I use all the time is to heat the part with the hole in it to cherry read then strt placing synthetic oil on the threded area as it cools it will pull it in and the synthetic oil willlet it work at a hotter temp and still leave it hot to try and move it (and rust is soft metal that will become "ball bearings" on a microscopic level and help it release) and heat and oil and move it and keep it up and usually it works free but you do need good wrenches for this (the 7.99 set from big lots aint gonna cut it).
A third which I dont like but one of the techs at work will use his air hammer to deform the nut on innter tie rods to free them.My problem is that if the hole in the nut has an internal dent it leaves 2 valleys on each side and lets them lock up even worse and if the person doing it is stupid it can destroy AND lock the nut nearlt permanently.
Good Luck
Lee Abbel

07-12-08, 05:09 PM
i dont think anything beats heat when it comes to rusty bolts... those are my thoughts

07-12-08, 11:02 PM
That's one way to bump a dead thread.......Might also try a product named PB Blaster. It works.

07-13-08, 03:52 AM
Mouse Milk is the favorite of the aircraft industry. http://www.mousemilk.com/

09-02-08, 06:52 PM
When heating and removing bolts depending on the size of them determines pretty much the measures you use at removing the bolt. You need to know a few things about the bolting.
What are the materials the bolt is in? Is the bolt held in with a heli-coil? Size and material of the bolt? What application is the bolt used for lube oil system, or water coolant system? Is it a hex head, or an allan head?

Removal of allan head bolts have some advantages over hex head bolts. Firstly, if the allan head starts to strip it can have a small peice of allan stock welded into the allan socket. This ensures you can use impact tooling effectivly on the bolt. Depending on the thread diamater of the bolt will determine the size of the impact used on the bolt. The thread diamater of of hex bolting can be determined because the head of the bolt for "standard sizes" is exactly one and a half the thread diameter size. A simple example can be seen in a hex bolt that accepts a 3/4" socket it will have a thread diamater of 1/2".

Knowing the materials of the bolting and what it is bolted to are crucial if you decide to go with heat. Reason being is dissimiliar metals have differing properties of heat transferance and disipation. If the bolt is in an aluminum block I would suggest you soak it in penetrant for several hours if not days. I do not suggest using that PB junk others have suggested I dont know how well it works but can tell you that KROIL is simply amazing. w w w.kanolabs.c om/google/ .. I use this all the time when working it does what it says and saves allot of knuckles from being skinned from splipping on a wrench under full load. If you do use heat on a mild or hardened steel bolt after it has been soaked in penetrant you have a limmited window of opportunity to remove it since the aluminum will absorb the heat and be the same heat as the bolt rather quickly. I suggest that you get the head of the center of the bolt cherry red and soon as it goes black from being cherry then you work on getting it out I would suggest using impact tooling and heat both together. If you do not have an impact gun you can use a slugging wrench as suplement if you have room to swing a hammer and strike the wrench.

If you start moving the bolt shortly after heating it I suggest you work quickly "not carelessly" on removing the bolt reason being is once the bolt and the block are at the same thermal growth the bolt may just simply stop moving from being extracted. If the extraction of the bolt simply stops halfway out and wont budge anymore a few posibilities may have occured the bolt may have developed a gaul or simply the heat transferance and expansion of the materials are the same. Either case try a little more force if it dont budge any longer then call it a day soak it again and then resume heating the bolt again once both materials are cooled.

Broken bolting
Many times broken bolts if ground flush can be extracted with a small hammer and a prick punch. If the shaft of the bolt is not corroded and used on say a lubrication system once you start tapping on the bolt it will work its way out. You would do this with a small ball peen hammer and the prick punch set at roughly a 45degree angle. You may have to make a few stake marks and keep changing position in the bolt shaft so you have the best swing and still be comfortable. Again penetrant and using finesse will get these out.

Broken bolting that is corroded can be removed how some have suggested by welding a head of a bolt onto the broken shaft. Only problem that may happen with disimiliar metal properties would be potential heat transfer and expansion growths. If this method does not work after you let the bolt and block cool you should consider grinding the bolt flat to the block or structure and use a various amount of cutting tools.

It is important that if you do resort to using cutting, grinding or drilling tooling that you practice good FME=Foreign Material Exclusion. You must cover any ports, holes or crevices with barriers. Your barriers can be sponges with lanyards attatched to plug holes. Taped off poly plastic and other various plugs. I suggest you keep an good FME log sign everything in and at the end sign everything out. Each barrier should be numbered and logged this will prevent you from leaving something where it shouldnt. Each tool should be logged in this will keep you from losing something where it doesnt belong.

Grinding and Cutting Tools.
So you have a broken bolt cant weld anything to it and it is flush to the surface of the block. No worries if you have the tools to do the job. Some people prefer drilling holes into bolts with a mag base drill and then using easy outs to extract the broken bolt. There are advantages and disadvantages to this. The advantage is if the bolt is not overly hard to turn you can farily easily use an easy out. If it is BALLS TIGHT then you risk the chance of breaking a hardened steel easy out inside an equally messed up bolt. If you do break the easy-out inside the bolt then you need to extract the peice by drilling or probing it with a dentist pick.

If you know the bolt is BALLS TIGHT then there are other options you can use. You can use left hand drill bits by using a centre punch you need to get dead centre of the bolt shaft from there you need to gradually increas the size of the drill bit. Eventually with a left hand drill bit the bolt will just walk out of the hole. If this does not happen then eventually you will wear the bolt so thin you can collapse it in the hole using a prick punch and a ballpeen hammer.

The other option you can use is drill the center of the the bolt and then use a die or pencil grinder and slowly move circles inside the shaft of the bolt. The end result will be you caving the bolt in with a hammer and a prick punch.

When using your drilling and cutting tools I would suggest for FME purposes barrier off the area below where you are cutting and or drilling have a helper use a shop vac to suck up any shavings of cuttings as you work. put a high strength magnet near the bolt being worked on so to catch any shavings. Use a small pen magnet to remove any shavings or chips as your working I would suggest doing that periodically.


The removal of bolting from heli-coils are pretty much like removing any other bolting. The difficult thing about heli-coils are that they tend to make extracting corroded bolting a bit more difficult. For the most part if you use heat get the head of the bolt cherry red and then soon as the red turns black perform your impact extraction. If the heli-coil does start backing its way out with the bolt do not panick many times a heli-coil will back out slightly but not all the way. If a heli-Coil extracts itself less than a thread do not try pushing or putting the heli-coil back in the hole. Instead you can use a grinder with a wafer wheel and cut off the peice of the heli-coil protruding out of the flush hole. If the heli-coil does extract out of the hole more than a few threads you should consider a few optional guidlines. Does the heli-coil have one and a half 1+1/2 the thread diamater inside the hole. If this is true then cut off the portion that has backed out and you should be able to safely re-use the heli-coil. If it does not then you should find a replacement for the heli-coil.