Reconditioning Nuts and Bolts

[Deano400]

Hi, does anyone have any advice on how to recondition nuts and bolts? I am particularly interested in how to coat the  engine nuts and bolts on my CB400/4.

[Nurse Julie]

What are you actually trying to do with the nuts and bolts ?, are they standard or allen headed ?. If your wanting to keep what you have, Zinc plating is a good way of sprucing them up.

[Deano400]

Thanks Julie . Yes, considering zinc coating but not sure if the threads would be any use after being coated. Might try cold spray on the heads and see what it looks like.

[Nurse Julie]

We have parts zinced regularly and never have a problem with threads. The art is in your cleaning prior to zincing, what crap you leave on will be under the zinc when finished or the zinc won't even stick in places.

[Deano400]

Sold! I think I'll give it a go. Thanks. 

[Nurse Julie]

We use Allenchrome near York. Very reliable and you get a lot done for not a huge amount of money. I think the batch we have there being done now weighed about 7kg and we should get some change out of £40. We take them there but you can send them by post as well.

[AshimotoK0]

We use Allenchrome near York. Very reliable and you get a lot done for not a huge amount of money. I think the batch we have there being done now weighed about 7kg and we should get some change out of £40. We take them there but you can send them by post as well.

Welcome to the mad SOHC UK world ..my 400/4 is the same Varnish Blue as yours.

Dumped a mammoth load of parts in at Allenchrome before I went on holiday. I always get great service from them and really nice people to deal with BUT make sure you prep the parts the best you can, as it's not cost effective for them to do it for you. What I do is degrease in thinners to get rid of the main oil and grease, then wash in boiling hot water with washing up liquid or Jizer then remove zinc plating with the Ashimoto alkaline strip (documented in another post) @70C in an old slow-cooker, then I bead blast them with dry 0/50 glass beads and then degrease again in isopropyl alcohol. Sounds like a lot of effort I know but the parts look great when they come back. They commented in Allenchrome how squeaky clean my bits are    so I must be doing something right. If you can't bead blast then a rotary wire brush gives a good finish.

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[Nurse Julie]

That all looks lovely Ash but, do you know where they all go??? 

[AshimotoK0]

That all looks lovely Ash but, do you know where they all go??? 

Funny enough that's exactly what Simon at Allenchrome said Julie .. and the answer is yes  . That's about 20% of the parts they have done for me so far BTW !

The spoke nipples and points plates were yellow passivated. They can't do black pass. though .. I think the little brackets on the rear indicators on the USA 500K0  that hold the rubber bits may have been black passivated originally as are some airfilter/ carb clamps. Gateros plating sell the black pass fluid for DIY but it's very expensive.

[Nurse Julie]

  You know more than me then Ash. I couldn't even pick out the bits for my CB550 that were in with a load of CB750 bits, luckily someone in this house knows where every single nut, bolt, washer etc goes, so I don't need to !!!. I think we are up to about 30kg of bits done over the past couple of months and more ready for collection now.

[Deano400]

Thanks Ash. Like the look of the finished parts. Will try mine using your process. Just one question about springs, how well do they coat considering the spirals are touching?

[AshimotoK0]

Thanks Ash. Like the look of the finished parts. Will try mine using your process. Just one question about springs, how well do they coat considering the spirals are touching?

Just stretch springs slightly between two pegs/bolts on a strip of clean steel. TBH those big springs are still available new and not too expensive, so I have bought quite a few new ones. It's the tiddly little bits that are unobtanium or mega expensive where replating deffo saves you  loads. Allenchrome have never lost any of my parts which is very reassuring and they don't take ages.

Here is my brew. OK you can use 'Brick Cleaner'  acid if you wish (contains dilute Hydrochloric acid) but my 'brew' is much gentler on the base material and we used it where I used to work.

To make up 1 litre of stripping solution:-

100 grammes ---  Sodium Hydroxide  (Source B &Q, Wilkinsons, Pound shops ect)

90 grammes --- EDTA---- (EthyleneDiamineTetraAcetic acid)  Source:   http://www.ebay.co.uk/itm/130544728488?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

4 grammes ----  Trimetholamine --- Source :    http://www.ebay.co.uk/itm/321368003934?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Immersion is at 70 degrees C +/- 5 degrees for about 20 minutes ( or until the bubbling stops  ).

[AshimotoK0]

Sodium hydroxide -caustic soda --  available in pellets from Wilco, B&Q, some poundshops etc

http://www.ebay.co.uk/itm/EDTA-1kg-60-00-4-/291837238776?hash=item43f2daddf8:g:dd4AAOSw5b1XI0x1

best price I can find for EDTA (Its used as a cure-all by health buffs now---may have bumped the price up).