polishing up the engine block

[wayanlam]

hi all,

im a little new to this, but im about to strip the old flaky paint off a 2 stroke engine block from an RX 100 (yamaha)

im contemplating to leave it unpainted, and just polish it up and put a clear coat. is that possible?...

ive searched and read it up a little and seems like some people suggest to just polish it, and re-polish every now and again (quite a lot of work). while others say its possible to use a high temp clear coat.

will a clear coat stick to a polished surface?

im wondering if it isnt better to use high temp black paint for the long run maybe...

[CThunder-blue]

Clear coat will not still well to a polished surface. When you polish, you are reducing the pores in the surface, which the clear coat/paint uses to bond. Also, clear coat dulls the polish look so the hard work you will have done will just go to waste. I would definitely go with the high temp satin black.

[Racer x]

I polished my engine cases .it is a lot of work. First you have to sand and sand till you can't see ANY scratches. Then polish .
The paint will not stick. Nothing will stick. I use never dull and mothers and wax and they are grayer now than when I first did them but still shiney. I would suggest sand blasting to remove the paint then ultra fine paper to get to the polish stage.
This thread needs pictures

[ako]

BBQ paint (black) is a good cheap option. I have even painted 2 stroke expansion pipes with this.

[wayanlam]

Originally Posted by Racer x

This thread needs pictures

ok ok, ill take a coupe "in progress" pictures.

whipped out the paint remover (evul nasty stuff that) and started stripping the smaller parts last night.

the engine has this slight metal corrosion under the original paint, and its basically possible to scratch it off with my fingernails, so removing the paint wont be hard. its the fine sanding, and polishing that will take a while.

i started to take pictures while i deconstructed the bike, in case i needed reminders on where the cables went,

its gonna be a fun ride once we put her back together and get the engine running.

i also took the top end of the engine block off, and saw a small chip in the edge of the piston. im guessing we will most likely need to replace that, the rings, and get new gaskets.

then also hope that the carb still works... it was sat in the garage for 2 years with fuel in it! ive NEVER seen a carb that gunked up. it was literally like scraping old chewing gum out of there! lol.... i was too busy cleaning that i didnt think about taking pictures, should have tho~

ill try and remember to take some pics later when i get home and post some here

[wayanlam]

might have to take on the exhaust with some BBQ paint, atm its rusty chrome, and looks terrible. has quite a few dents in it too, lol

they used to take this bike out in the fields and use it as a motocross.... and dropped her a lot

[CThunder-blue]

Originally Posted by wayanlam

might have to take on the exhaust with some BBQ paint, atm its rusty chrome, and looks terrible. has quite a few dents in it too, lol

they used to take this bike out in the fields and use it as a motocross.... and dropped her a lot

LOL. Hillbillies will be hillbillies, no matter what culture your from.

[wayanlam]

forgot to take a pic before removing the tank and saddle, oops~


left~


right~


peeeeling...


engine out!




hmm... worked on it for about 2 minutes with 1000 grit sandpaper and some metal polisher

i can already tell that its gonna be a pita to clean all of those FINS, lol...

[Buffalony]

Originally Posted by wayanlam

I can already tell that its gonna be a pita to clean all of those FINS, lol...

You cant stop now

Thanks for the pics. Keep us posted

Maybe find a local sandblaster. You could probably remove all fittings and protect what you dont want blasted. Would give you a big headstart. just a thought.

[wayanlam]

i would be afraid that they dont have much experience sandblasting engines, and might do more damage than good. well maybe there is a workshop thats done some previous work cleaning up old engines, but i wouldnt know where ask, or who to trust.

also the budget of my friend who owns this bike is really quite minimal, so its gonna be down to some good old fashion elbow grease.... sandpaper and water is cheat at least!

[nickadolph]

Get a drill mounted red scotchbrite pad, should get everything except corners.

[wayanlam]

here is a progress update... about 3 hours of sanding by the two of us... i literally sanded my hands raw, started to bleed on two fingers before i realized, HAHA....




can see what it looked like by comparing it to the other side that we havent started on yet. the larger piece isnt done yet. had to stop sanding cos my my bo-bo, lol



still need another one or two sanding/polishing sessions to get the rest of the engine parts as clean and shiny as the engine head and the small cap/cover that we managed to finish.

[Racer x]

Great job . Sanding sucks hu??

[wayanlam]

i actually enjoyed watching the parts go from that ancient peeling black paint to that shiny bling finish! i would have kept sanding for another hour had the fingers not given out.

at first my friend thought i was crazy.... but by the time we were done, he was dissapointed that we couldn't get the lower piston sleeve polished up the same way, rofl.

[CThunder-blue]

There are better & easier ways to remove black paint than sanding. Sanding should only be after the paint's removed. Media blasting would be the best. You can also use paint thinners. It's easy and painless.

[Jesse8931]

Take the motor completely apart since you have to replace crank seals anyways. then take the case, jug and head to a guy who does walnut blasting and then you will be good to go.

[wayanlam]

i have paint remover. we used that to start with, otherwise it would have taken wayyyy longer than it did to clean those parts up xD

gonna stick with that and sandpaper for now. i think a couple more sessions and we will be done with the rest of the engine )

[Jesse8931]

Originally Posted by wayanlam

i have paint remover. we used that to start with, otherwise it would have taken wayyyy longer than it did to clean those parts up xD

gonna stick with that and sandpaper for now. i think a couple more sessions and we will be done with the rest of the engine )

Make sure you replace the crank seals if not your wasting your time.

[Racer x]

this is a shot of the right side covers. Chemical stripper then sand blast then sanded and polished..
It is a lot of fun watching the parts shine.

[wayanlam]

all the seals will be changed out, the engine will be totally overhauled. piston needs to be replaced, there is a chip in it~

the carb took me a while to clean out, sat for 2 years with fuel in it... used a whole can of carb cleaner on that baby. rofl...

probably gonna repaint the rest of the bike myself too. its gonna be an fun 1st time for me. ive watched others repaint bikes, etc. really curious how the rest of this lil project will come along

[ducducgooseit]

Sometimes cowhide gardening gloves will protect your fingers while you sand. Refinishing on a strict budget comes down to elbow grease though.

And a reminder: Are you sanding out of doors? It would be best for your health to keep as much of that fine sanded paint out of your lungs as possible.

[wayanlam]

gloves wouldn't give me any feel with what im doing. fingers are healed up now, waiting for my friend to come by again for another sanding session, lol...

with the use of the paint remover we are definitely doing this outdoors, with running water, etc.

we are also wet sanding this, going from 180 grit, down to 320, then 1000 grit. so there is no dust from sanding with the water.

[kkim]

what about using some air tools, or at least a dremel, to help speed up the sanding and polishing.

[wayanlam]

dont have a compressor, nor a dremmel in my small artillery of tools, although both are on the "wish list"

might borrow a compressor from work when we need to start painting the bike though.

[wayanlam]

another update, took the engine apart a little more:











lil bit of a chip in the piston, lol...

time to replace that~

its late, so just posting up the pics, peace

[ducducgooseit]

Originally Posted by wayanlam

That'll polish out.

[kkim]

for cleaning up the engine case halves, if you're not going to paint it (I didn't), I've found wd40 and 3m scotchbrite works wonders to clean up old, stained, unpainted case halves.

also, paint stripper makes an excellent gasket remover.

[ducducgooseit]

Wayanlam - what came of this

[wayanlam]

the owner of the bike got really really reeeally... slack, and stopped coming over for ages. since im helping him out for free, and im not getting anything out of this besides the experience, i dont plan to work on the bike on my own without him to give me a hand.

everything is still sat in small piles all over the floor, sigh~

he did come by the other week to pick up the bikes frame since he wanted to drop it off somewhere to get it repainted. i think he got tired of stripping the paint on the engine block, hehe

ill update again once there is some movement again.

in the meantime i just bought a 1989 Honda 115cc bike, sorta like a CB for a little over $200

dropped it off at the mechanic to check the engine, do a full service, and possibly do a little porting while we are at it. gonna mod it into a retro/classic looking bike.



something along these lines if possible

ill post pics up when i start working on that, hehe...

[the big mike]