Honda CB750 Sandcast
The Restoration Shop => Engine - Cosmetic Only => Topic started by: Wayne on December 05, 2012, 09:00:09 am
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Has anyone had a look at what Andy Morris does for his aluminum engine component finish? It's a ceramic coating with a "polished aluminum" type finish. The parts look pretty amazing to me, especially the alt. cover! Sure would save a lot of work on my end. Anyone have any thoughts? No, I know it's not original but as Steve has said over and over, "it's only original once". :)
(http://img155.imageshack.us/img155/3355/cer3kd9.jpg)
(http://img182.imageshack.us/img182/4219/oh6fp9.jpg)
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I strongly considered doing that a few years back when I was restoring my k0. I actually had my covers boxed up to ship out and changed my mind at the last second. What scared me away was it appears to have an "orange peel" finish. From a normal viewing distance they look gorgeous but up close I didn't think they looked correct enough. I'm reconsidering it right now as I try to get all of my covers polished. I like that the finish is super consistant and it probably does a nice job of covering up small imperfections and seems like it would last forever. In a way that's a negative for me too in case I didn't like it and wanted to go back to brushed aluminum. I always thought I should get a tappet hole cap done just to see what it looks like. Maybe I will. I would be very interested in opinions on this too.
Mark
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I wonder what company Andy used? I know most will send you a sample done on something like a length of exhaust pipe. I got this one a few years back when I was doing a BSA project. The sample does show a bit orange peel. Perhaps if we can find out who Andy uses we should get a larger non sandcast part done Mark? If it's not TOO expensive I'll pay for half. I'm really HATING rubbing away on these covers! :(
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I had the name at one time but can't find it. I wanna say it's in Colorado. I think I got it from one of Andy's threads on the SOHC4. I'll try to track it down. If I can't find it we could PM him. He hasn't been active here for a while but he is on the SOHC4.
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My problem would be if the finish got scuffed or grazed a bit, with polished or brushed ally it is repairable , with this then it would need recoating , at probably a high cost, it is tempting , although i prefer the brushed finish with clear powder coat, or as my k1 has polished and lightly oiled to stop oxidising
Pete
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KP can probably remember, but as i recall, the finish does not let the aluminum finish look natural, sort of faux.
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Andy did give me the contact details but that was a few years back now so I'll have no chance of finding it. the trouble I find with photographs is they don't show enough detail. We've all experienced this when we've bought parts off eBay, in that the part looks better in a photograph. What I see as looking great is as Mark said, there is an orange peel look to the finish when viewed up close and I'm not sure I want that.
The only finish I would probably consider is clear powder coat as I've had no success in any clear coat product sold in this country. There is a company here which paints a 2 pack clear on alloy but it looks like a 2 pack clear product. Personally I think the approach Mark B and Steve V (ie: spending hours and hours getting the finish correct) is the one that probably gives the best results. I'm no expert on this though KP
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Reading KP's post, ditto what KP said.
It takes me around 15 hours to polish all aluminum parts on a 750.
I will differ w/ KP about me getting the finish correct.... i like bling... ;D Deep shiny aluminum finish which matches the beeuteeful chrome and paint. :o
I know Chris R did quite a bit of experimentation using different grits of sand paper, but then more importantly, IF i recall correctly his final finish was obtained using different grades of steel wool. Chris, at one time sent me close ups of his covers and they looked REALLY good, IMHO.
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It takes me around 15 hours to polish all aluminum parts on a 750.
I will differ w/ KP about me getting the finish correct.... i like bling... ;D Deep shiny aluminum finish which matches the beeuteeful chrome and paint. :o
:( Looks like I have more sanding and polishing to do. I'm kind of with Steve on this one. I like bling as well but I WAS hoping to save a LOT of work and farm it out to a Ceramic coater. ;D
I have experimented with Eastwoods Diamond Clear Coat. It goes on nice over a polished cover but the question is, will it stay? I heated the piece in an oven, let cool, repeat, etc. put in cold and now it has sat in my basement for months. There are no signs of peeling or cracking.
http://www.eastwood.com/ew-diamond-clear-gloss-bare-metal-aero-11-oz.html (http://www.eastwood.com/ew-diamond-clear-gloss-bare-metal-aero-11-oz.html)
Steve, did you use a Clear Coat over your "bling" polished aluminum pieces?
I guess until I make a final decision on what the final finish will be, I'll just keep sanding and prepping the pieces, mainly that PITA valve cover so I can get my engine back in the frame soon! :)
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Wayne, my covers are:
au na·tu·rel ( nch-rl, ō nä-tü-rl) adj.
1.
a. Nude.
b. In a natural state.
2. Cooked (polished) simply.
Seriously, the way Chris prepped and finished is covers, i believe would take no more time than blinging them out. I think i forgot to mention Chris covered them with some type of clear coating.
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I have always hand finished the various covers. Polishing mops are great, but can tend to blend detail. Hard going by hand when covers are damaged / corroded, but working down the various grades of cloth (or even starting with a file) from 120 through to worn out 1200 grit (dowels, spatulas, etc used to help get in and round detail areas) gets a finish which (to me) is close to Honda's. Scotchbrite can be used to good effect to get the linish effect marks in the right direction, or to dull back any over-polished areas. Bling is not for me, but each to their own. I do not these days clear coat any of the covers, not really having found a reliable long lasting product which turns out right here in the UK. On any rider, "natural" finish covers are more easily maintained than clear coated, which inevitably chip / weather and deteriorate.
15 hours probably a fair estimate for reasonable condition covers, just seems like much longer, especially when finger ends become raw and bleed!
As always, no short cuts when you do it yourself.
Cheers - Chris R.
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Chris, the ally covers and fork lowers on my K1 which i bought from you have a lovely polished finish, i clean them with autosolve, and then wipe them with ACF50, it leaves that lovely clean satin look,and is easy to maintain, just do the above once a year, i will be doing the same finish on my K0
I have a new alternator cover, which will be used on my K0, very dissapointed with the finish on it, it has the usual Honda linished finish with clear coat, that looks great but where it comes up to the edges and hard to get places the finish is very poor, there is no attention to detail however they do it now , just wondering was this always the case or were early covers given more attention
Oh and BTW your bike collection is very impressive, i though i was the only mad one but seems like your collection has expanded quite a bit over the years, what a great pension fund
Pete
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Surprising just how many of us suffer from excessive numbers of "boys toys" out in the garage. Pension fund - one day maybe; for now I just enjoy owning and riding.
There is of course also some comfort to be had from the fact that you can own these sorts of things, enjoy them, and likely get your money back some day. No fun to be had in having the cash in the bank knowing you WONT get it all back some day!
By the way Pete, just moved out of Sheffield to somewhere with more "toy" storage capacity.
Cheers - Chris R.
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OK, I THINK I have made my decision on aluminum component finish. It was evident on all of my aluminum parts that they had a clear coat on them so perhaps that's how they will leave my shop? (pending what Mark and I find out about Andy's ceramic process and whether it looks natural enough)
I have one piece where the original clear coat and underlying finish is in really good shape. (it was covered in grease and road grime when removed) My plan is to strip the clear on half of the flange, and use the exposed areas of the rear flange as a "guide" for refinishing my other components. When I clear the finished piece I will be able to see how it looks against the still original clear coated half of the flange.
For now I will just start cleaning the pieces up, working up to 1000 grit or so and see where we are. Enough time will have passed by then that we should have some answers I hope. :)
Now my big question is the wear from the chain guard. Is there supposed to be any lip around the circumference of the flange or did my guard wear it approx half way through?? (see pic)
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i can't recall any lip. the face extending to lip (front visible periphery) is flat smooth surface. Hard to fathom how a plastic chainguard could scratch into a smooth surface.
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i can't recall any lip. the face extending to lip (front visible periphery) is flat smooth surface. Hard to fathom how a plastic chainguard could scratch into a smooth surface.
Looks like mark's 97 experienced the same fate Steve. I can't tell if the "lip" goes full circumference or not.
(http://cb750sandcastonly.com/coppermine/albums/userpics/10002/DSC09203.JPG)
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This is not uncommon - #5528 had the same problem too. If you still have the chain guard and look in the corresponding area you might find flakes of aluminum in the chain guard. This no doubt would accelerate the wear.
It's a hard area to weld fill too- easily distorts. I just opted to get a good second hand one.
Regards,
Steven
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Thanks Steven
My parts list keeps growing and growing. :( :(
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Just check with your local welder- the lip on mine was too thin, however if yours is solid enough on yours, you may be able to weld it.
There are differences in the sprocket carrier markings that I have noticed. Some are stamped, some are cast I believe. It's always better to restore the part which came with the bike unless absolutely necessary to replace it.
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I'll have my welder have a look. Thanks. I would say from my pic this unit was "cast". Going to need a short chain guard now. Wore the heck out of it!!! :(
(http://cb750sandcastonly.com/smf_forum/index.php?action=dlattach;topic=850.0;attach=1237;image)
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Hi Wayne, check the underside of the carrier. There are numbered markings. I believe yours should be stamped, but later carriers, even those with the sepearate sprocket bolts, have the number cast (raised as opposed to stamped).
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Yep, it's stamped. "13". The 1 is stamped very bold and deep, the 3 not as much.
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If the groove worn by chain guard is not too deep, is it possible to turn off (matching the taper of plate) the groove, then polish to hide the turn marks ?
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The "step" goes from the good area at 4.30 MM down to 1.60 MM. Looks like I have about a 2.7 MM gouge. :( I would never have believed the chain guard did that until I looked at it. :(
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If the groove worn by chain guard is not too deep, is it possible to turn off (matching the taper of plate) the groove, then polish to hide the turn marks ?
That's what I'm going to try to do to mine. I'll post results.
Mark
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Mark is this part unique to the sancast or is a 69/70 K0 one the same?
If same its a no brainer to me replace would surely be much easier than all that machining
Pete
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Wow. that's deep.
Outward appearance, i don't think there'd be any issue using a 69-70 or probably even K1.
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Wow. that's deep.
Outward appearance, i don't think there'd be any issue using a 69-70 or probably even K1.
Yes, it was wearing away for a while. Wore the lip right off the chain guard. :( I'll have my welder/machinist see what he thinks before I replace the flange. Like Mark says, for everything that goes well with these things something seems to go wrong!
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Nearly every one I've had has had this problem to some degree. No doubt the presence of road dirt trapped in any oil, etc adds to the abrasive action going on between chainguard and sprocket carrier. I have usually manged to clean them up using various grades of emery cloth. Just takes time.
K1 uses the same part number item, so should be possible to find a better replacement if the wear is too deep - unless of course the worn one is unique to the bike by virtue of casting differences / marks, etc.
Cheers - Chris R.
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I don't know how unique my part is being "stamped" with number 13. (unlucky in this case) As you can see in the side view the wear is quite substantial. Way beyond polishing it out. It woul dhave to be built up and resurfaced. I contacted my machinist to see what he thinks.
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Wow. That side view really shows the depth of damage... :o
fwiw, here is a link on ebay to what appears an unblemished K1 spkt.carrier...
http://www.ebay.com/itm/HONDA-CB-750-K1-SOHC-1971-CUSH-DRIVE-REAR-SPORCKET-HUB-DRIVE-HUB-NO-RES-/281037155043?pt=Motorcycles_Parts_Accessories&fits=Model%3ACB&hash=item416f1eaae3&vxp=mtr (http://www.ebay.com/itm/HONDA-CB-750-K1-SOHC-1971-CUSH-DRIVE-REAR-SPORCKET-HUB-DRIVE-HUB-NO-RES-/281037155043?pt=Motorcycles_Parts_Accessories&fits=Model%3ACB&hash=item416f1eaae3&vxp=mtr)
i DO have a sprocket carrier which i assume is originally from a "K0" or earlier bike because the carrier has the 45t "large/small" hole sprocket which appears to have not ever been removed going by the lock tabs appearing undisturbed. However, i see no stamped or raised numbers on the backside of carrier... ??? And, it has a faint wear circle, suggesting the chain guard got in to the carrier; this wear circle could be polished out. Wayne, if you want it, it's yours for the shipping.
But... the one on ebay appears unblemished.. ? and, probably same as one i have... :)
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Steve
Much appreciated. I'll let you know as soon as I hear back from my machinist. I couldn't find any stamping on my flange at first either. On very close inspection I found the unlucky "13". It's quite small. The "1" is less than 1/8".... the "3" even smaller.
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Hmm. where are markings located specifically ?? (assuming my carrier has markings, i'm surprised i can't see it since i have 20/20 vision at 2 inches)
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Steve. Takes me a couple of seconds to find these little rascals even once I knew where to look. On closer inspection I uncovered a second 3, we now have 3 - 13. :)