Honda CB750 Sandcast

Restoration of Sandcast #97

markb · 814 · 285318

greenjeans

  • Newbie
  • *
    • Posts: 47
    • View Profile
Mark,  those gauges look great.   Did you re-use/re-plate the backs or did you buy new backs ?     Would you happen to know the part number for those ?  The plates on the back of my gauges seem to look different (mainly the areas that are cut out where the cables for the tach & speedo attach.) than the ones that I am seeing on ebay or the parts fische I see at my Honda shop.


markb

  • Moderator
  • Hero Member
  • *****
    • Posts: 1249
    • View Profile
I bought them from Marcel.  The ones I have were pretty badly rusted although I still have them and I might try to have them replated.  I believe the early part numbers are 37236-300-009 for the speedo and 37244-300-009 for the tach but I don't think you'll find NOS.  Yamiya has them, both styles.  Here's a link to the correct ones I think:
http://www.yamiya750.com/index.php?main_page=product_info&cPath=37_98&products_id=465
and the other version if you want to compare.
http://www.yamiya750.com/index.php?main_page=product_info&cPath=37_98&products_id=466
A little spendy, almost $200 for both but if you can't find anything else...
Mark B
1969 CB750 sandcast #97 restored - Sold Restoration thread link
1969 CB750 sandcaxt #576 - Sold
1969 CB750 sandcast #1553 - Sold
1969 CB750 sandcast #1990 - Sold
1969 CB750 sandcast #5383 restored - Sold Restoration thread link
1970 CB750 K0 restored - Sold
2010 H-D Tri Glide Ultra Classic (Huh?)


markb

  • Moderator
  • Hero Member
  • *****
    • Posts: 1249
    • View Profile
I finally have my zinc ready to drop off.  Part of the reason that it took me so long is I’m doing everything for 1553 too so I have just about everything for two complete bikes plus a few extras.  I’ve got everything from three engines too although I don’t worry about replating most of the internal parts.


I probably have 25 hours just into this bin full of screws, nuts, washers, pins, etc.  Besides wire brushing and cleaning, I ran a tap or die in or on every threaded part.  Maybe a little anal but maybe one in ten had some corrosion or gunk on the threads.  I’ve found that the more work I put into it the better they turn out.  I’m not sure where I got it but I had it in my head that there was about 5 lbs. of fasteners on one bike.  So I put this bin on the scale and it was 22 lbs. (10 kg. for you metric guys)!  No wonder my fingers are raw!


I’ve got all the carb screws and linkage and bowl clips too.  While I was at it I even threw in some of my homemade tools.  Which reminds me, I should throw in the Honda tools that need plating too.


My chrome should be done soon.
Mark B
1969 CB750 sandcast #97 restored - Sold Restoration thread link
1969 CB750 sandcaxt #576 - Sold
1969 CB750 sandcast #1553 - Sold
1969 CB750 sandcast #1990 - Sold
1969 CB750 sandcast #5383 restored - Sold Restoration thread link
1970 CB750 K0 restored - Sold
2010 H-D Tri Glide Ultra Classic (Huh?)


markb

  • Moderator
  • Hero Member
  • *****
    • Posts: 1249
    • View Profile
Someone on the SOHC4 site commented about not knowing where all my zinc plated parts go when I get them back.  I’ve got spreadsheets with size info to help me indentify the parts.  A couple of guys have asked me for copies and I’ve been thinking that maybe they might be helpful for others and I’m more than happy to share them.  I started a separate thread here:
http://cb750sandcastonly.com/smf_forum/index.php?topic=747.0
Mark B
1969 CB750 sandcast #97 restored - Sold Restoration thread link
1969 CB750 sandcaxt #576 - Sold
1969 CB750 sandcast #1553 - Sold
1969 CB750 sandcast #1990 - Sold
1969 CB750 sandcast #5383 restored - Sold Restoration thread link
1970 CB750 K0 restored - Sold
2010 H-D Tri Glide Ultra Classic (Huh?)


markb

  • Moderator
  • Hero Member
  • *****
    • Posts: 1249
    • View Profile
I’m way over due for some updates.  Some of you may be wondering about my alternator cover welding repair.  Shortly after I gave the stuff to the welder he had a death in the family and has been spending all his time settling the estate and getting a house ready to sell and hasn't been taking on any welding jobs.  I talked to him last week and he promised he’d have it done by the end of April.  I know, it’s been months, but I really don’t want to have anyone else do it and I don’t need it yet anyway.

Also I’ve been busy working on the reproduction mirror stems.  I'll post an update on that soon.

I finally got the chrome plating back.  It was quite a load since I had some stuff from 97 and 1553.  Overall I’m quite pleased with it.  I’ll never be totally happy because I’m too picky.  If anything some of it is too good, in other words, better than original as far as the finish before plating.  But I don’t think I’ve ever seen restored chrome look original and everyone seems to be OK with that.


I did duplicate parts like fenders so that they could compare fender them for straightening but I threw in some other duplicate parts too.


The plater seemed to do the best on the bigger stuff like the wheels.  Except for being over done they look great.  They were in pretty rough shape.


My biggest complaint is the bolts for the brake disc.  There’s no sharp edges left on the hexes so in my opinion they’re way overdone  Supposedly they were too rusty and they had to polish them much to make them look OK.  I’ve got some nice original ones that I might have to “borrow” from one of the other bikes so it’s all good.


Obviously I don’t need any of this yet so I just wrapped everything up real good and put it away for now.  My zinc should be done soon.
Mark B
1969 CB750 sandcast #97 restored - Sold Restoration thread link
1969 CB750 sandcaxt #576 - Sold
1969 CB750 sandcast #1553 - Sold
1969 CB750 sandcast #1990 - Sold
1969 CB750 sandcast #5383 restored - Sold Restoration thread link
1970 CB750 K0 restored - Sold
2010 H-D Tri Glide Ultra Classic (Huh?)


kp

  • Administrator
  • Hero Member
  • *****
    • Posts: 1801
    • View Profile

Steve Swan

  • Hero Member
  • *****
    • Posts: 2705
    • View Profile
    • cb750sandcastonly.com
GULP !  I hav'nt had a "whole sandcast" plated since around 2005.  Seems like the cost for all the parts re-chromed was around $1500+  The high degree of work and expense we go to make these things dear.  Yes, they like to get after those delicate little hexes with their big 5hp polishing lathes.

If parts are not rusted, corroded, etc; i'm wondering what the chome plate would look like if the steel was buffed and not polished..  Or, not even buffed but left "plain" after the chrome is removed.  i've never asked "my" plater...  i don't know what bare steel finish/surface looks like, after "my" plater removes the chrome using electrolysis.  If or if not electrolysis to remove old chrome alters original surface of steel.

i wonder what plated parts Honda used a copper base, if any..   Or, if all the plated parts from Honda were only nickel and chrome with no copper base.


vnz00

  • Full Member
  • ***
    • Posts: 237
    • View Profile
Hi Mark, looking good.  My parts for 5528 are in being rechromed as well.

Regarding Steve S' comment on copper base, I thing the main parts which were polished were coppered.  I had my fenders (guards) panel beaten and where the file finishing was done, there was defn a copper base.  Id say the same for the starter motor, clutch and points covers too.  Id imagine anything which was 'show chrome' according to Honda would have been coppered.

I dont believe the Nuts n Bolts which have chrome finish to have been coppered.  I know the chrome brake line bolts are unpolished, but have a nickel/chrome plate in lieu of the later zinc finish.  Essentially just a brighter finish and harder surface, to the existing rough natural steel. 

The rear axle and swingarm bolt are probably just flash chromed also, with a light polish to the show surfaces.  No copper base.  Brackets etc Id say the same. 

Some of these parts you can still buy used in nice shape now, 40+ years on.  If I come across them, Ill reuse them for the reason that I dont like overpolished bolts etc.  Also I had wheel bolts/axles done on my K0 when I restored it, and if they use a copper base etc. they end up too thick for use.

The bare steel surface is a dull grey colour after electrolysis.  The polished copper, prior to nickel, is also not as I expected - it is a burnished/rainbow effect copper layer, rather than a consistent shiny green colour.

It is impressive to watch the electrolysis take chrome off - literally a matter of minutes to do it.  My plater told me its 30-40amps passing through the part to the solution, so I dont think it would take long to erode the part if not carefully watched ;)

It would be great to be able to polish/buff the small stuff ourselves to get the desired results, but most places would look at you like you had two heads for asking.... My plater scratches his head enough when you ask him to leave casting marks and polish lines through the parts, ruining his opinion of his job being well done.

Just out of curiousity Mark, how did your diecast parts go (i.e. Indicator Bases and Fuel Cap)?  There is good information out there about rechroming diecast parts, and why they are hard to chrome in the first place (if they already have pits).  Some places will use the same process used for non-metallic parts (i.e. using a conductive resin/paint coating) on die cast parts.  just wondering if they did it with your parts?

Looks like the cost to rechrome is the same in the USA as it is here in Oz.  The main cost is labour - especially if they are using copper base to fill pitting...


markb

  • Moderator
  • Hero Member
  • *****
    • Posts: 1249
    • View Profile
GULP !  I hav'nt had a "whole sandcast" plated since around 2005.  Seems like the cost for all the parts re-chromed was around $1500+ 
This was a whole sandcast + and the cost was $1800 which I didn't think was too bad.

Just out of curiousity Mark, how did your diecast parts go (i.e. Indicator Bases and Fuel Cap)? 
Actually, they turned out great.  They didn't do anything special that I know of.  I'd shoot some pics but I already have them safely packed away.

Steve and Steven, thanks for the interesting comments.  I wish I had some parts that were good enough (no rust) to replate without the polishing.  It's difficult to convey to these guys just what you're looking for.  Even if the boss understands, he's not the one prepping for plating and the minimum wage employee isn't going to risk his job by under doing it.  Per your advice I am going to have some fasteners done nickel/chrome.  In particular I had 3 oil bolts done and I believe they are way too shiny.  Of course it didn't help that they polished them after I told them not too.  In retrospect I think I may have brought too big a batch and ended up with too many different instructions for different parts.
Mark B
1969 CB750 sandcast #97 restored - Sold Restoration thread link
1969 CB750 sandcaxt #576 - Sold
1969 CB750 sandcast #1553 - Sold
1969 CB750 sandcast #1990 - Sold
1969 CB750 sandcast #5383 restored - Sold Restoration thread link
1970 CB750 K0 restored - Sold
2010 H-D Tri Glide Ultra Classic (Huh?)


vnz00

  • Full Member
  • ***
    • Posts: 237
    • View Profile
I've learnt that with the special stuff, I box the parts separately, and leave a list/photos of what needs to be polished, which cast areas remain etc. I have a pretty good work relationship with my plater  though. 


markb

  • Moderator
  • Hero Member
  • *****
    • Posts: 1249
    • View Profile
I guess this is a case of 1 step backwards and two steps forward.  About a month ago I decided that the painting I had done last year was too shiny.  I had my painter do some experimenting and after looking at some samples decided to have everything repainted.  I tried taking some pics to compare old and new.  It’s next to impossible to get a good shot of something black.  But you can kind of tell in this pic, the new is on the left.  In person I think it turned out fantastic and will look much more correct.


Mark B
1969 CB750 sandcast #97 restored - Sold Restoration thread link
1969 CB750 sandcaxt #576 - Sold
1969 CB750 sandcast #1553 - Sold
1969 CB750 sandcast #1990 - Sold
1969 CB750 sandcast #5383 restored - Sold Restoration thread link
1970 CB750 K0 restored - Sold
2010 H-D Tri Glide Ultra Classic (Huh?)


Joe K

  • Sr. Member
  • ****
    • Posts: 268
    • View Profile
Looks good, Mark.  It appears that the paint layed down smoother too.  Very little signs of orange peel.  I can relate to you when you say that you needed to re-paint it with a little less gloss.  Things like that bother me in my restorations also.

Joe K.


markb

  • Moderator
  • Hero Member
  • *****
    • Posts: 1249
    • View Profile
I finally have my zinc plating back, most of it anyway, after dropping it off in March.  It‘s probably my fault for using this guy but I’ve had good results with him in the past and what I got looks good this time.

I haven’t found anyone in my area that will do small batches of zinc for motorcycle parts.  This guy, who does mostly chrome, does all the prep and has a buddy of his do the zinc at another shop.  Turns out he had a stroke and couldn’t do it.  I didn’t find this out until over a month after I dropped it off.  So it took a while to get the parts back and to another source for plating.  That explains why it took so long.
Now as to why I don’t have it all.  I had a small bag of parts to be yellow zinced.  The bag was labeled and in a bigger box with big parts like rear sprockets, brake arms and stays, etc.  Guess what happened?  I have yellow sprockets, brake arms and stays, etc.  ::) So they're going to redo it.  I guess it’s really not a big deal because I don’t need the parts yet. 
But I have learned one thing, I’m going to quit telling people that there’s no rush on getting stuff done.
Mark B
1969 CB750 sandcast #97 restored - Sold Restoration thread link
1969 CB750 sandcaxt #576 - Sold
1969 CB750 sandcast #1553 - Sold
1969 CB750 sandcast #1990 - Sold
1969 CB750 sandcast #5383 restored - Sold Restoration thread link
1970 CB750 K0 restored - Sold
2010 H-D Tri Glide Ultra Classic (Huh?)


markb

  • Moderator
  • Hero Member
  • *****
    • Posts: 1249
    • View Profile
Being busy with boating and fishing this summer and working on the mirror stems, I haven’t got much done, although the stems are for #97 so I guess that’s something.  I did finally get my alternator cover back from my welder too.




I have to admit this part is a little scary but I’m committed now.  I figure it can’t look worse than it did with all the gouges.  I’m not sure when I’ll get to it but my next step is to clean it up and then get all the covers “brushed” and coated.

« Last Edit: August 23, 2012, 01:31:16 pm by markb »
Mark B
1969 CB750 sandcast #97 restored - Sold Restoration thread link
1969 CB750 sandcaxt #576 - Sold
1969 CB750 sandcast #1553 - Sold
1969 CB750 sandcast #1990 - Sold
1969 CB750 sandcast #5383 restored - Sold Restoration thread link
1970 CB750 K0 restored - Sold
2010 H-D Tri Glide Ultra Classic (Huh?)


vnz00

  • Full Member
  • ***
    • Posts: 237
    • View Profile
With a little patience, and a flat edge, those welds will clean up nicely :)
My alternator cover had a pretty bad dent in the bottom chamfer - I didnt think it would come out looking nice.  A little heat got it out.
I think the scariest part is the discolouration after welding, but it is only on the surface.

Have fun!