[Advise Needed] Correct way to finish off Stator + Clutch Cover and Cylinder Head

[joshes]

Hi all,


I hope I am entering the correct forum discussion room.

I am currently restoring a 1977 GS750. The intention is to get it back to its original state (or even better with modern technology).

I am now asking advise from friends of GS owners, who are more expert in restoration for this bike.

For a start, I have 2 questions:

1. For the Stator and Clutch Cover. It seems there is a light clear coat (some kind of varnish) coated over these covers. Is it true? What alternatives do I have to replace such clear coat. I trust there is no aftermarket coat that is heat proof. Any advise (please kindly see pictures attached of both covers).

2. Cylinder head and engine block. What is the best advise to give in order to finish the cylinder head and the engine block to look like 'new' (please kindly see pictures attached of the cylinder head).

Thank you all for the advise.

Josh

 

[Agemax]

hi josh,
there are many options you have and many differing opinions from members here.none are right or wrong, just a matter of personal preference.
the clutch and stator covers can be rubbed down with wet and dry to get the factory clear coat off and then polshed, or chromed. some guys on here do re clear coat them but i personally dont like that.
the only way to get the block and head back to factory finish is to get them vapour blasted.this will give them a clean "new" appearance and if done correctly will include a rust inhibiter to prolong the appearance. when done it could look like this...

 

[joshes]

Hi Agemax,

Many thanks or the response. I have to say that I am impressed with what you have done with the engine. Did you use the dry and wet to polish down coat on the clutch cover? Can I ask you if what number wet and dry do you use? Did you use buffing machine to to the final polish?

As for the engine block - i live in Indonesia, I don't think that there is vapour blaster here. Before I make the full judgment on the availability, can you explain what is vapour blaster? Is it similar with sand blaster but using water vaporisation instead? How about using sand blaster? Is it too hard for the block?

Thank you so much for the info.

 

[Agemax]

depends on how bad your clutch cover is. start off with maybe 600 grit wet and dry and keep getting finer, finishing with a 1000 or 1200 grit. then polish, by hand or with a buffer if you have one.
vapour blasting is basically wet sand blasting, but using finer sand, much less abrasive. sand blasting would be ok but you have to make 100% sure it is washed out thoroughly before rebuilding the engine, and i mean 100% sure

 

[joshes]

Got it!

Going back on the vapour blasting - have you heard of bead blasting. Any comments on this. The only reason for asking is that there is a limited 'blasting' options in where I live. So, just to make sure i choose the right method.

Thanks a lot mate!

 

[Agemax]

bead blasting is fine as long as you mask off any delicate areas ie. camshaft journals etc, and as stated wash out after, then wash again and again and again until you are sure it is 100% clean

 

[joshes]

I have looked again and found out the camshaft cover (at the top) has yellow-ish coat. I can not work out what is it bt surely it is not a silver coating (which I initially assumed) nor clear coat. Do you have any information of what it is?

Thanks again!
Josh

 

[Agemax]

may be sprayed by a previous owner but that can safely be bead blasted to return it to a nice bare aluminium finish. also will give it a good surface finish should you wish to spray it

 

[joshes]

If I were to sprayed it - what would be the recommended type of paint to choose? Heat proof paint or just standard paint - or perhaps powder coat? What's you thoughts on this? Thanks again!

Josh

 

[Agemax]

heat proof paint would be your best bet although powder coating would probably be ok, but more expensive

 

[joshes]

Powder coat might be cheaper here in comparison with imported heat proof paint. normally heatproof paint is imported from the US or UK.
So, if i choose to powder coat - what should I be concern about? Any particular method of peeling off the old paints? Or should I be concerned with particular areas? I just need to make sure I take all the precautions before proceed.
Again, thanks for the information!

 

[Agemax]

get the old paint bead blasted off. most powder coaters will do this anyway. just make sure the gasket surface and the inside is not coated

 

[nvr2old]

If all you're looking for is to refinish the covers the way they looked from the factory. Save yourself all the money on blasting (unless you're painting the pieces) and just use good 'ol fashioned elbow grease. Strip the old clear finish off with aircraft paint stripper (use gloves, this stuff is toxic). It'll come right off. Your covers might need something more aggressive than 600 to begin with. I'd start with 180 wet, lots of water..get the impurities off, then proceed to 320, 400, 600, 1000 and then maybe 1500. One or two sheets of each is all you need. Follow with a good aluminum polish (Mothers is great) with a pad that you can put in your power drill, or just polish by hand. It's time-consuming, but it's very inexpensive, and the results will blow your mind.

 

[Agemax]

If all you're looking for is to refinish the covers the way they looked from the factory. Save yourself all the money on blasting (unless you're painting the pieces) and just use good 'ol fashioned elbow grease. Strip the old clear finish off with aircraft paint stripper (use gloves, this stuff is toxic). It'll come right off. Your covers might need something more aggressive than 600 to begin with. I'd start with 180 wet, lots of water..get the impurities off, then proceed to 320, 400, 600, 1000 and then maybe 1500. One or two sheets of each is all you need. Follow with a good aluminum polish (Mothers is great) with a pad that you can put in your power drill, or just polish by hand. It's time-consuming, but it's very inexpensive, and the results will blow your mind.

that has already been mentioned for the covers but you cannot get the surface finish on a cam cover or cylinder head with wet and dry,it needs blasting to get in all the nooks and crannies

 

[nvr2old]

Sure you can. It takes effort. I've done valve covers lots of times. Most people just don't want to devote the time. Seems like a lot of people are looking for a quick fix, but in reality, patience and persistence are all that's needed. The head/cylinders/block are a different subject. If you're going to repaint them, even sanding those parts as much as you can is safer IMO then blasting. Getting parts clean is the key.

 

[Agemax]

Sure you can. It takes effort. I've done valve covers lots of times. Most people just don't want to devote the time. Seems like a lot of people are looking for a quick fix, but in reality, patience and persistence are all that's needed. The head/cylinders/block are a different subject. If you're going to repaint them, even sanding those parts as much as you can is safer IMO then blasting. Getting parts clean is the key.

for a perfect finish, or a key finish for painting it is impossible to do the head or block by hand. blasting is the ONLY way as long as they are washed properly after.
you mention a quick fix! sanding all the cooling fins is a quick fix and will never be as good as blasting.spend the time masking up the key areas and get them blasted and you will get a better finish than you ever will with sanding inbetween cooling fins!
show us some pics of your hand finished head/block handywork

 

[nvr2old]

Here's an XL250 Honda that I did, before and after. All sanding.

Here's my GS1000S engine right before painting it and then all done. Lots of sanding and cleaning, but no blasting. The valve cover is finished in 600, every nook and cranny, and it could just as easily been taken to 1500 and polished. Same for all the covers. A paint stick wrapped in sand paper makes short work of doing in between fins.

 

[nvr2old]

Here's an example of a cleaned, sanded, and hand polished engine with no sand blasting. Not saying blasting's better or worse. Just saying it can be done very well w/o blasting. Results will vary either way. It's how much you want to invest, time or money. I got a lot of time in these, but almost zero cost other than paints and polishes.

 

[duaneage]

Soda blast

Soda blast

I used a small tank style sand blaster but loaded it with baking soda.That's the same sodium bicarbonate used to brush teeth, cook, clean and deodorize the fridge. I bought 50 pounds of baking soda for 58 dollars. I used about 30 pounds to clean all the old paint, corrosion, and grease off my 400 yamaha engine. The finish was perfect. And when you are done just hose it off and then dry the engine with air or a leaf blower.

I plugged all the holes but even if it gets in the engine the baking soda just dissolves. It doesn't harm you or the environment, you can even eat it. When done put a hose on the driveway and it disappears.

Just don't do it on the grass, the baking soda will kill the grass by making the soil too alkali. If you do get a pile on the grass and it turns brown just dig it up and use new dirt and seed.

I have some pictures somewhere of the results, I'll try and dig them up..

 

[joshes]

Hi NVR2OLD and all other members who have contributed to the thread,

First of all thank you for all the useful inputs - as well as awesome pics! Man, I envy you guys in the US and UK! The limitation of doing so is high in Jakarta. However, the good news is that manual labour is cheap - I can have as many people I want to scrub the parts.

However, I still have a (possibly silly) question. Did you (any of you guys) take apart the engine when you polished them? As the engine I have now works fine (well it sounds fine though) - and I am contemplating to take apart the engine in order to polish the parts.

It would be silly if, for the sake of cleaning the outer parts of the engine - I have to take apart the engine and once it is put back together, the engine does not run as well as before. I would bang my head to the wall! I don't want the cosmetic works to be detrimental to the running of the engine.

The least I am planning to do is to take off the engine from the frame (like NVR2OLD) put it on a stand.

I am not a mechanic, although I have a friend who is a savvy mechanic. He is happy to help undone the engine from the frame, but he is also unsure if taking apart the engine is such a good idea.

Any thoughts on this?

Thank you all for the useful inputs!