bolt stuck in block.. tap & die?

[phatmanmike]

i have 3 different motors , each with 1 bolt that has snapped off in the block..<br />1972 50hp evinrude, water jacket bolt<br />1972 6hp johnson water jacket bolt<br />1986 tohatsu 8hp cyl;inder head bolt<br /><br />each of these bolts is stuck in the block, can i drill out the old bolt and re-tap the hole.. id rather do this myself if possible ad not pay a machine shop... is this something i can do myself? ive looked at taps and what type of steel(hardness) would i need to tap into these various blocks. i assume they are all aluminum, so can i use the general "hardend" steel or do i need the "high speed steel"<br /><br />please help as i am dumb to this topic<br /><br />m ikey

 

[Boomyal]

Re: bolt stuck in block.. tap & die?

I would apply a good penetrant liberally. Let it sit over nite. Take a solid center punch, make sure you center it perfectly, and give it a number of good raps. Then drill center of stud for appropriate sized easyout. If it doesn't start to back out right away, keep it saturated with the Liquid Wrench and keep rapping on it, with some force. Retry easyout. <br /><br />The bigger you can drill the hole in the stud without going off center, the easier it will be to remove. Drilling and rethreading aluminum should be your last resort.

 

[kd6nem]

Re: bolt stuck in block.. tap & die?

Drilling and rethreading aluminum should be your last resort.

Definitely, Boomyal is very right. And the only thing worse is often what happens just after you break the easy out off because you put too much side load on it or used too small a one. Just BE CAREFUL! Centered perfectly means you can have a bigger hole. Bigger hole means bigger easy out. Bigger easy out means harder to break. SOMETIMES heating the aluminum gently with a heat gun or torch can help loosen things up too, just use good sense about it. Try to not heat the stud. If in doubt let it (and you) cool off before trying again. You will get it, but patience gets more done than impatience. Drill deep enough but not beyond the stud. Don't use a cheap imported chinese easy out- might be too brittle. I like the squared off type but the twisted ones work also.

 

[Terry H]

Re: bolt stuck in block.. tap & die?

...and I'll add one more thing...when you drill the bolts out don't worry about the bolt and drillbit getting hot, the hotter the better 'cause it will help break the threads loose...just a Thought

 

[Paul Moir]

Re: bolt stuck in block.. tap & die?

I hate easyouts. If I were in charge of it, their inventor would not enjoy their afterlife.<br /><br />If there's anything left of the bolt to grip with a set of vice grips, you should begin by trying to wind them out. If you don't have one already, invest in a propane torch - or better yet a propylene or mapp brazing torch. Practice trying to melt some scrap aluminum with it first - it'll give you a good idea on how much you can heat something before it melts. HINT: it's almost impossible to melt the larger aluminum castings with any of the above mentioned torches.<br />Between heat and penetrating oil, you can remove any fastener as long as your careful - provided you can get a grip on it. Needless to say, you're gonna need vice grip brand vice grips, or some supurb knockoff, to grab it well enough.<br /><br />If your broken flush, what I do is carefuly file the top as flat as possible, punch the exact centre of the bolt stud, and drill incrementally larger holes until there's just the thread left behind. Then I pick out the first bit of thread (sometimes I get lucky here and the whole thread comes out like a spring), and tap the hole out with the exact size tap as the original bolt. Rather than cutting a new thread, the tap just cleans out the old thread.<br /><br />Paitence is key. If it's beating you, walk away from it and come back another time. It's easy to go from bad to worse.<br /><br />...quitely grumbling about people who profit from the desperate. No good good for nothins who kick a guy while he's down...

 

[phatmanmike]

Re: bolt stuck in block.. tap & die?

bolt broke about 3/4 inch inside block of the tohatsu.. thats the one i just did tonight. i drilled the bolt down to the end with just one sized up drill bit and then re-tapped the hole a size larger, so now it take a bigger around bolt, but it works and seals good. <br />1 down... 2 to go

 

[jim dozier]

Re: bolt stuck in block.. tap & die?

If its not too late don't use larger bolts, install a helicoil. If you get the busted stud out, buy a helicoil set and tap the hole for the appropriate helicoil. The helicoils (stainless steel) allow original bolt sizes and resist further stuck bolts. <br /><br />Do not use EZouts on outboards, the grip of corrosion on marine outboards exceeds the torque rating of the EZout and you will have to discover methods of removing EZouts in addition to stuck bolts.<br /><br />If there is any of the bolt sticking up, weld a nut onto the top. The heat of welding helps loosen the stud. In addition to the liberal addition of penetrating oil, use a propane torch to heat the stud/bolt. When drilling out bolts (as a last resort) I find it helpful to have onhand a carbide tile cutter bit in a Dremel tool in case the pilot hole starts to wander off center. You can (carefully) recenter the pilot hole with the carbide bit.

 

[AndyL]

Re: bolt stuck in block.. tap & die?

I have seen in a ship yard a set of left handed drill bits which worked incredibly well in circumstances like you have. Obviously you need a drill that will rotate backward and just go slow. The deeper you go the more chance the friction of the bit will break out the stud.

 

[KCLOST]

Re: bolt stuck in block.. tap & die?

Kind of on this subject, is there any recommended lubricant or anti-corrosive compound that can be added to the studs before re-insertion....<br /><br />Since they are stainless, it may not be necessary, but just wondering...<br />I got lucky and all mine came out fine, without any evidence of corrosion. But I wonder if I should have added something to them before re-installation.

 

[kd6nem]

Re: bolt stuck in block.. tap & die?

Anti-seize compound is usually an excellent idea, unless the torqe spec is for dry bolts only.<br />If chasing the threads with a tap, using a bottoming tap is a better idea. In any case, don't just run it to the bottom of the hole. Stuck, broken taps are evil!

 

[eric1]

Re: bolt stuck in block.. tap & die?

just for the record in about 10yrs of working on cars and trucks by far the best method for removing stuck bolt is to first heat the area around the bolt as hot as you dare(its aluminium)then shock it by pouring water over it then heat it again,then use what ever you decided to use to get it out, if your not flush i must recommend you use a twelve point socket just a bit smaller than the bolt. Tap the socket on the end of the bolt shaft this method has never failed me!!!!!!<br /><br /> Just BECAREFUL with the heat.

 

[Paul Moir]

Re: bolt stuck in block.. tap & die?

KCLOST - There's two ways you can look at the stud issue. Anti-sieze is one, and works pretty good. Another is to use sealer on the screw threads to keep the water out of the joint, which works quite excellent. Anti-sieze on stainless to stainless threads is a good idea, because it will help with galling.<br />Around here, if you don't do something with the threads they'll permanently corrode together. Stainless included.<br />Actually, stainless seems worse to me sometimes.