Amazon: New (to me) 1963 Volvo 122

[Othen]

Originally Posted by Laird Scooby

You know you'll fit the matching mirror on the drivers door Alan!

Can i suggest Rivnuts instead of Rawlpugs? I'd go for aluminium ones seing as the loading isn't high and you don't want to risk deforming the door while setting them but they would take up the excessive clearance. Steel Rivnuts would be better from the point of view of galvanic corrosion but offset against the risk of deforming the door i'd go for aluminium versions.

As you had predicted Dave, I've fitted the driver's side mirror today:



... visibility is about the same on the driver's side, but the mirror is a little larger and so gives a wider field of vision, also the chrome plating is not pitted - so good all round.



Having matching mirrors is certainly an improvement - I think the Peugeot items look just fine on GAM.



Fitting was much easier this time round. The rivnuts I have are M5 and a little too large for the existing holes both in the door and the mirror. I could have modified both to suit but decided to use rawlplugs again for now and order some M4 rivnuts, which should be just about right. The rawlplugs on the passenger's side seem strong and firm enough.

All in all a good fix for very little money.

:-)

Alan

[Ron Kwas]

LS;

If using Alu Rivnuts and they were in direct metal to metal contact (no paint or other separator from body steel), they would be particularly susceptible to galvi-corrosion because of the disadvantageous Cathode to Anode Ratio.

For "rubber rivnuts"...search also "Wellnuts".

Cheers

[Othen]

Originally Posted by Ron Kwas

LS;

If using Alu Rivnuts and they were in direct metal to metal contact (no paint or other separator from body steel), they would be particularly susceptible to galvi-corrosion because of the disadvantageous Cathode to Anode Ratio.

For "rubber rivnuts"...search also "Wellnuts".

Cheers

Many thanks Ron. Dave pointed this out somewhere above, and that was another reason for not using the aluminium rivnuts I had. I’ve ordered some rubber M4 rivnuts, which should be easy to install from outside the motor car.
Alan

[142 Guy]

If you want to avoid a galvanic cell, matching your metals is the best solution. However, if you check out a table of galvanic potentials you will find that the common aluminum alloys and mild steels are not that far apart on the galvanic table. If galvanic action does take place, it will be the aluminum rivnut that will be sacrificial, not the steel body. The bigger issue would be if you use a stainless steel mounting screw in the aluminum rivnut because SS and Al are farther apart on the galvanic table leading to potentially faster sacrifice of the aluminum rivnut.

The wellnuts that I have seen typically have a brass (brass like) threaded insert in the rubber plug. In this case you may not be home free. You don't have a galvanic cell with the door skin because of the rubber insulator; but, you might have a significant issue with the mounting screw. A cadmium or zinc plated mild steel screw and a brass insert is actually fairly far apart on the galvanic table with the screw being sacrificial (a bigger problem that the aluminum rivnut in the steel body). Some stainless steel alloys are close to brass; but, some SS are quite far apart from brass.

Nothing is cut and dry! I have used aluminum rivnuts without issue on my 1971 142E; but, I do live in a climate that is much drier than yours and I don't drive it in the snow (or intentionally in rainstorms because I think the wipers seem to be a design after thought). If I did drive it in the snow, corrosion at the aluminum rivnuts would be the least of my corrosion concerns.

[Othen]

Originally Posted by 142 Guy

If you want to avoid a galvanic cell, matching your metals is the best solution. However, if you check out a table of galvanic potentials you will find that the common aluminum alloys and mild steels are not that far apart on the galvanic table. If galvanic action does take place, it will be the aluminum rivnut that will be sacrificial, not the steel body. The bigger issue would be if you use a stainless steel mounting screw in the aluminum rivnut because SS and Al are farther apart on the galvanic table leading to potentially faster sacrifice of the aluminum rivnut.

The wellnuts that I have seen typically have a brass (brass like) threaded insert in the rubber plug. In this case you may not be home free. You don't have a galvanic cell with the door skin because of the rubber insulator; but, you might have a significant issue with the mounting screw. A cadmium or zinc plated mild steel screw and a brass insert is actually fairly far apart on the galvanic table with the screw being sacrificial (a bigger problem that the aluminum rivnut in the steel body). Some stainless steel alloys are close to brass; but, some SS are quite far apart from brass.

Nothing is cut and dry! I have used aluminum rivnuts without issue on my 1971 142E; but, I do live in a climate that is much drier than yours and I don't drive it in the snow (or intentionally in rainstorms because I think the wipers seem to be a design after thought). If I did drive it in the snow, corrosion at the aluminum rivnuts would be the least of my corrosion concerns.

Thank you - that is fascinating. Your last sentence sums it up nicely: whilst driving my 60 year old motor car around in our damp and sometimes cold climate I probably won’t worry too much about the tips of 4 plated machine screws reacting with the brass inserts of the rubber rivnuts :-)

Alan

[Othen]

Originally Posted by Othen

I doubt very much that the brushes are 59 years old, so they were probably replaced in the past 2 or 3 decades. The solenoid did look like it had not been touched, I noticed the insulated barrier between the two large terminals was broken off - perhaps age, vibration... who knows?

The exciter terminal on the old solenoid looked a bit scabby, that could have been the problem I suppose. It wasn't really worth investigating though, the new one works perfectly, and I think I discern that the starter is spinning a bit faster on start-up (that may be wishful thinking on my part).

Everything got a clean up - hopefully that will be good for a couple of decades now. I'm not to worried about the commutator cover needing a nudge with the oil filter grips to get it moving - it had probably been in the same place for something between one and six decades.

I've just been out for a test drive with several starts - all seems fine. I'll have to wait until everything is cold in the morn to give it a proper test.

:-)

Alan

PS. I'm pretty sure I won't need it, but Amazon sells the correct brush holder set for my starter (001311001) by AS-PL (SBH0122S) for only £20.08:

https://www.amazon.co.uk/AS-PL-SBH01.../dp/B08WLZ3TVD

The intermittent starting problem raised its head a few days ago. Having done everything I could think of, I turned my attention to the only significant part of the external starter circuit I'd changed, this momentary switch:



I tried just rotating the switch around - and it worked straight away. Nothing else had changed so I'm guessing the switch just has one spot where it doesn't make a very good contact. I seem to have sorted the issue, and it would appear that all I'd need to do if it reappears is spin the switch a little to fix it. My previous work changing the solenoid and cleaning the commutator and brushes may well have been superfluous, but won't have done any harm.

I have a spare momentary contact switch, which is rather more substantial, but I'd have to drill a bigger hole in the dash to fit it so I'll just see how it goes for the time being.

:-)

[Laird Scooby]

Instead of fitting a larger switch in the dash to cope with the current demand of the solenoid circuit Alan, just use a relay and keep the chrome starter button to operate the relay coil with the main current for the starter solenoid going through the relay contacts.

It's what many manufacturers have done for decades and is simple enough to do.

[Othen]

Originally Posted by Laird Scooby

Instead of fitting a larger switch in the dash to cope with the current demand of the solenoid circuit Alan, just use a relay and keep the chrome starter button to operate the relay coil with the main current for the starter solenoid going through the relay contacts.

It's what many manufacturers have done for decades and is simple enough to do.

Agreed Dave, it would be an easy thing to do, but I don't think that is the problem. I think the switch itself probably has a small sector inside that doesn't give a good contact, if I rotate it around a bit it seems to work fine. If that is the case it could happen if it powered a relay (although admittedly the current required would be smaller, so it might still work).

Alan

[Laird Scooby]

Originally Posted by Othen

Agreed Dave, it would be an easy thing to do, but I don't think that is the problem. I think the switch itself probably has a small sector inside that doesn't give a good contact, if I rotate it around a bit it seems to work fine. If that is the case it could happen if it powered a relay (although admittedly the current required would be smaller, so it might still work).

Alan

The problem is Alan, by switching the much heavier current (35-60A) for the solenoid using just that switch, it's likely to deform and/or burn the relatively small contacts within the switch. Adding a relay will improve the reliability of its operation and the reason why manufacturers did it in the first place.
By rotating the button, you will be rotating the contact inside the switch to a "fresh" area, you will shortly run out of fresh areas and need to replace the switch. Much easier to renew a relay but considering that most relays will comfortably handle 30A (there are some capable of 40A in a standard 4-pin arrangement), that time will hopefully be many more miles down the road - pun not intentional but fits nicely so i'll leave it!

[Othen]

Originally Posted by Laird Scooby

The problem is Alan, by switching the much heavier current (35-60A) for the solenoid using just that switch, it's likely to deform and/or burn the relatively small contacts within the switch. Adding a relay will improve the reliability of its operation and the reason why manufacturers did it in the first place.
By rotating the button, you will be rotating the contact inside the switch to a "fresh" area, you will shortly run out of fresh areas and need to replace the switch. Much easier to renew a relay but considering that most relays will comfortably handle 30A (there are some capable of 40A in a standard 4-pin arrangement), that time will hopefully be many more miles down the road - pun not intentional but fits nicely so i'll leave it!

Thank you Dave, all that is obvious, but I'm still not convinced it is the issue.

The solenoid (Bosch 033130203) is rated at 15A maximum and the momentary switch is only a few months old. I don't think it is gradually developing bad sectors, I think it probably had a manufacturing defect with one bad sector. That is my theory - I'm just going to monitor the issue, if it stays as it is now I'll suspect I'm right; If the MTBF becomes less I'll know it is failing and have to replace it, plus probably fit a relay at the same time.

Perhaps I should have explained Dave, that my reason for fitting a more substantial momentary switch isn't to handle more current (the one there should take 15A), but because that is what I happen to have in my auto spares box.

Alan