anti-seize with stainless bolts?

[robbyusa]

I just removed my power head again to replace motor mounts. I was amazed at how well protected the bolts were that I coated with ant-seize. They looked like the day I installed them after 5 years of hard use in the gulf of mexico. The only problem was the heads were rusted to nubs due to the fact that I never painted them after completing my rebuild project.<br /> Now I have to buy new bolts or pute old ones back with vise grips<br /> Do I buy stainless bolt or just replace with what I had from the factory and coat again with anti-seize but this time remember to paint heads of the bolts.<br /> I heard but am not sure I beleive that if I use stainless bolts that the anti-seize will cause corosion between the aluminum and stainless.<br /> If this is true I might avoid stainless bolts as I hear they are not considered to be very strong maybe being the reason I hear of so many breaking when being removed?<br /> Has anyone else heard of not using antiseize (weather it be nickel or copper based) on stinless bolts used in aluminum?<br /> I know I could use graese, permatex, or pipe dope with teflon on my stainless bolts but I am curiouse as to weather any one has experienced a real problem with anti-seize and stainless bolts?

 

[ob]

Re: anti-seize with stainless bolts?

I don't believe you would have any problem using graphite based anti-sieze,but I personally would just use a marine grade allpurpose grease on the new bolts.

 

[robbyusa]

Re: anti-seize with stainless bolts?

Permatex Corp. seems to sell 3 types of permatex <br /> 1) plane old anti-seize (can't find mention of ingriedients but wonder if this is the graphite you are talking about?<br /> <br /> 2)nickel based<br /><br /> 3)copper based<br /><br />By the way I heard a mechanic refer to how bad it would be to use grease with graphite in it on trailer wheel bearings. This is also a mystery to me. Any one know about this problem?<br />Thanks!

 

[Paul Moir]

Re: anti-seize with stainless bolts?

I know with some oils or greases you can run into a problem where the rollers actually slide rather than roll. Mabey this is what he was thinking of?<br /><br />The 'regular' Permatex antiseize claims to be a blend of grease, aluminum, copper and graphite. IMO, anything containing copper needs to be avoided where galvanic action with aluminum is a possibility, however I've seen many 'Marine' anti-seize compounds that are mainly graphite but contain some copper. So that's probably the best of those ones.<br />I think the best is to use a zinc or graphite-zinc based antiseize for going into aluminum, and that's what I personally use. Galling isn't a serious problem here afterall.<br /><br />But whatever you do, use something. Stainless seems worse to me for getting stuck into aluminum than steel bolts. That may be due to their weakness and breaking, but I think it's because of the stronger galvanic action.

 

[robbyusa]

Re: anti-seize with stainless bolts?

It is interesting to me to see the current drive towards more stainless bolts on outboards when I don't see a clear benifit other than shiny bolt heads. I wonder if steel bolts properly installed and painted wouldn't be cheaper stronger, and better than stainless. <br /> I still also wonder about the adversion to anti-seize even with its copper content especially since spark plugs have been coated with them in aluminum heads with success for years. The confusing part is Permatex claimes that there copper anti-seize is suggested for aluminum threads. If there are horror stories out there I hope to hear them before I have to live them but I am mostly trying to educate myself and my fellow classmates as to their options. <br /> I dont think for instance that grease, Gasket snot type permatex or pipe dope would be suitable for spark plugs because the heat would cook any of them. So there is at least one use for anti-seize out there but even then I understand that Mercury suggests dry threads with no oil on plug threads due to coking.<br />Thanks for the replys!

 

[Dunaruna]

Re: anti-seize with stainless bolts?

I'm a bit of a stainless fanatic, if the bolt is available in stainless I'll buy it. I always look for 3-16 grade.<br /><br />Been using a graphite/copper based anti-sieze for years - spark plugs, every nut & bolt, rollers etc. Never had a problem with reactions or powdery alloy.<br /><br />A moderator on another forum hates anti-sieze on plugs (into alloy heads) and claims that all sorts of reactions can occur (something about harmonics ?)- I've never had a problem. <br /><br />Aldo

 

[Paul Moir]

Re: anti-seize with stainless bolts?

Shiney bolt heads are a clear benefit. <br /><br />Seriously though, I doubt you'll ever have a problem as long as you seal the bolts using goop or anti-seize and don't give the salt water a chance to get in between the two. <br />Somewhere back in the Mercury section you'll find a post I made where I was trying to remove the 5" leg extension on a little outboard. The extension was simply an aluminum housing with two long stainless studs run through it. Over time, the aluminum corrosion grabbed the smooth parts of the studs so tenaciously that it took hours of pounding, prying, soaking and heating to separate them. And these were originally holes the studs slipped simply through in order to hold the housing in alignment. <br />'Course, you don't run into that sort of problem with spark plugs in aluminum heads - there's no galvanic action going on there since you don't have an electrolyte. I suspect the reason outboard spark plugs don't stick so bad is simply that they usually don't have much of a threaded portion. And you end up removing them every year or two for replacement anyway.<br />I agree with you that goop is probably going to burn up on a few of the bolts that you're replacing, since some of them go into some pretty hot places in the engine. I use goop on all my 'below the waterline' fasteners like the lower unit bolts or water pump housing screws, where I'm afraid the anti-seize will end up washing away eventually. I've never had a problem removing one that's been sealed this way.

 

[Mark42]

Re: anti-seize with stainless bolts?

I have never heard of stainless being a weak metal. If anything, it is hard. Ever try to cut a stainless bolt? Based on my personal experience I would say it is more brittle than regular steel, but not more so than some hardened grades. Ya think?

 

[Dhadley]

Re: anti-seize with stainless bolts?

There are many grades of stainless. Some ss things cut very easily. Some rust. It just depends on what grade you're dealing with.

 

[robbyusa]

Re: anti-seize with stainless bolts?

I don't mean to knock stainless because shinny bolts are a plus. I would deffinitely prefer them to the rusty bolt heads all over my motor.<br />Thinking about it more I guess what I dont like are Factory installed stainless bolts that are pute in with locktite that dose little to nothing to prevent them from corroding permanantly into their holes. Maybe we should completely dissasemble our motors when we buy them to do what the factory should have done in the first place especially on our stainless bolts.<br /> By the way Aldo thanks for your remark I will buy 3-16 stainless bolts and anti-seize them into place and assume I will get them out as well as my steel bolts unless someone can come up with that horror storie I was looking for?

 

[jim dozier]

Re: anti-seize with stainless bolts?

I would wonder about using graphite compounds with aluminum for the same reasons as copper. On the galvanic chart of dissimilar metals, graphite (although not a metal it is a very good conductor) would be higher than copper and at the opposite end from aluminum. Based on this (and not my personal experience) it probably won't corrode the bolt but might accelerate corrosion of the aluminum which is worse. The old fashion carbon zinc flashlight batteries were made of a graphite rod in a zinc (very similar to aluminum) can with an electrolye paste (very similar to salt water). Maybe you could charge your batteries with your head bolts.

 

[seahorse5]

Re: anti-seize with stainless bolts?

In many cases, certain types of anti-seize will "eat away" the aluminum threads in an outboard. Usually they are the gearcase fastening bolts and will loosen and fall out. The holes then need to be drilled out and tapped for a heli-coil thread insert.<br /><br />The best way to prevent salt frozen bolts is to use a marine grease such as Triple-Guard, Merc 101 or 2-4C on the threads. I've changed out water pumps 5 years after greasing the threads (in Southern salt water use)and the bolts come out easily with no salt buildup.

 

[robbyusa]

Re: anti-seize with stainless bolts?

Bush and anti-seize seem to have something in common You either love or hate it. I am a Bush lover as well as a ant-seize lover I wonder who you anti-anti-seize people support <br /> Isn't there someone out there who can tell me a horor story like I used X brand of anti-seize which is of the Y type on a Z material part while using W material bolt and it ruined the threads in the part? <br /> I have also read and seen all the books and charts everyone is refering to but what I dont understand is why it works so well.<br /> After 5 years of salt water running every thing from spark plugs to powerhead bolts look perfect in my motor. Today I even tookout the exhaust cover bolts just to see how they were doing.<br /> All is well!

 

[Mod2]

Re: anti-seize with stainless bolts?

Moving to General Discussion.

 

[Scaaty]

Re: anti-seize with stainless bolts?

Originally posted by Mark42:<br /> I have never heard of stainless being a weak metal. If anything, it is hard. Ever try to cut a stainless bolt? Based on my personal experience I would say it is more brittle than regular steel, but not more so than some hardened grades. Ya think?

Stainless is a very TOUGH metal. Dull your hacksaw blade real quick. Very mallable, and will twist in half easy when corroded together with aluminum. But if you stick a iron bolt in there, in saltwater, you won't have to worry about it being hard to get out, as it won't even be there. I use marine grease. And carry a full set of Heli-coils. Broke a prop anode bolt on my 280 and heli-oiled it.Sits all summer in salt. Wonder what will happen to that? Aluminum to steel to stainless! Maybe I should toss a little copper anti-seize in for good measure

 

[18rabbit]

Re: anti-seize with stainless bolts?

Any anti-seizing compound aside, aluminum and stainless steel are two metals to avoid in contact with each other in a marine environment. Where ss fasteners are used thru aluminum, the norm is to use a plastic sleeve/bushing between the two such that the bare metal of one does not come in contact with the other. Even when the aluminum is primed/painted, such as on masts, a plastic insulator can often be found between the two, and a plastic washer between the bolt head and the mast, another plastic washer between the ss washer/nut and mast on the other side.<br /><br />If the anti-seizing compound does not act as an insulator, the aluminum will suffer. Here’s an anti-seize insulating compound made for ss+aluminum.<br /><br /> http://www.spursmarine.com/tefgel5.htm

 

[kd6nem]

Re: anti-seize with stainless bolts?

I won't bet my life on it, but I'm quite certain graphite will not in itself cause galvanic corrosion. It is pure carbon, and has no H+ or OH- to help facilitate the electrolysis. (H+)+ (OH-)= H2O, water. Add Na+Cl- (salt from the sea), it gets even more interesting. Can't trust those darn +'s & -'s once they get loose. They're lively little suckers.<br /> EDIT: I'm not sure enough of my chemistry to know to what degree, but graphite is not necessarily as inert as I was thinking, if it is in the right environment for it to donate (or is it receive?) electrons it CAN theoretically play a part. Much as stainless can cause aluminum to corrode more than mild or carbon steel, graphite could perhaps add to the problem as well. <br /><br /><br />DHadly correctly states that there are many grades of stainless steel. Statements about one kind are often wrong about another. Those numbers means something. Relates to content alloyed with the iron. Yes 316 is very difficult to corrode, where 304 rusts easily. They are appropriate in different places. Not sure what SS bolts are made of or how they compare for torque, tensile, or shear strength or resistance to galling. If in doubt use original OEM style.<br /><br />Graphite is NOT suitable as a high speed lubricant, so said my HS chemistry teacher many years ago. Its atomic structure allows it to be very soft on one axis allowing it to be a good lube. But at higher speeds there can be a rotation of the molecules (as they shear off?) which causes the opposite chemical nature of carbon (other molecular face to be shown)- the diamond's characteristic of hardness. Hense abrasive at high speeds which might allow this to occur.

 

[Scaaty]

Re: anti-seize with stainless bolts?

Originally posted by 18rabbit:<br />[QB] aluminum and stainless steel are two metals to avoid in contact with each other in a marine environment. QUOTE]<br /><br />Then why do they sell stainless bolts with the anode that will screw into the aluminum lower unit and which you also should not use any coating so as to make good contact?

 

[phatmanmike]

Re: anti-seize with stainless bolts?

robby, because the the anode is zince, and will corrode before any others. its sacrificial. it doesnt matter if they are stainless and aluminum or not, because their on;y job is to hold on that zinc.

 

[kd6nem]

Re: anti-seize with stainless bolts?

Yes, and without the good electrical contact the anode does not protect much of anything. In any case, if those bolts did corrode, just cut them off. It is not like you've just wrecked a powerhead or lower unit if that happened. But this is what the sacrificial anode does help prevent.