Its all about how dissimilar steels, irons and aluminium alloy's react against one another. some steels when mixed dont react or see little reaction, others such as Para mentioned, stainless and aluminium will corrode like made unless you have a sacrificial anode to take the corrosion away. Large ships suffer galvanic corrosion and have big lumps of copper as the sacrifice. Somewhere in work we have the tables for the corrosion properties.
Plus a stainless stud plus stainless nuts will most likely see you winding the stud out every time as the nut galls (cold welds) to the stud once all the grease has gone..
FTFY Even in rivers and canals, I have Magnesium ones I think. Different metal required for salt water.
Yes.. its zinc. Makes it hard for me as when the tide comes in, the river is salt, but when it rains a lot it's more like brackish fresh water as the tide goes out..
Talking of canals and horses for courses for material resilience . lock gates were made of beech wood because they keep sound under water . But cut and left in the open rots quicker than any other hardwood .
I believe that steel canal boats usually have Magnesium sacrificial anodes, don't know what sea going ones have though. I thought lock gates were made of Oak, every day is a school day!
Maybe in electrical contact submerged in salt water but not on for the subject of this thread . All my 8/9mm studs are stainless and I’ve been using Stainless fixings in Aluminium for 30 years as an Engineer
I’ve seen it personally a fair few times on type 1 engines with stainless tinware screws into the alloy heads.
Good chance a lot are Meltman ..its just what i was told . It would certainly be good enough . There is another timber that is used but can't remember which . I should imagine at the time they would have used what was locally available and replaced if it went pear .
According to the C&R.T all current lock gates are made from sustainable grown green oak, but I'm sure you are right in saying that originally they would have used what was local
Maybe my woodwork teacher got it wrong ...he was the fella that told me . Just looked up ,beech woods durability increases massively if constantly soaked and was used for water wheels in the past and was used as an option to oak on lock gates ..presumably if oak was not available . Maybe it's me thats got it wrong not the teacher ...heaven forbid . I must say i have deviated massively from the initial subject .
not Aluminium cases tho Type 1 . My new Triumph motorbike Engine hardware iis pretty much all stainless Anyway I’ve never had an issue with a type 4 engine using stainless and both my Type 4 have stainless HX studs with copper coated nuts .
The T1 tinware can get wet but the exhaust nuts are generally very hot when they get splashed. So stainless into aluminium and wet gives electrolytic corrosion, stainless on stainless exhaust fittings have dry welding issues.. hence using copper coated steel nuts on stainless exhaust studs.
Sorted the stud ,mate of mine has a lathe so cut the thread down then cut the new thread with an m8 die ..a good quality one . Fitted a treat . Copper exhaust washers were well stuck OK when applied a bit of heat , annealed the new ones . The original Heat Exchangers are so much more heavier then the repro's
got one stubborn copper washer will not move almost welded to the head , applied some heat but loathed to go to far , have tried to chisel a groove to piggle the washer out ...still fast in . How crazy can you go with heat without wrecking the head ?
I think your grasping saying a type 4 H/X studs being stainless get splashed and corrode but I’d rather that than snapped off Chinese steel studs . You use Chinese steel and I’ll use 316 S stainless .
