Author Topic: Remove finish on motor case?  (Read 1423 times)

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Offline ChrisFMA

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Remove finish on motor case?
« on: September 25, 2017, 05:24:50 PM »
I've been cleaning up this bike and mother casing has a peeling finish on it. I'm sure it will come off completely with some solvent or very fine steel wool. The question is should I recoat it? I'm sure the finish was there to protect the case from oxidation or other environmental damage, but I'm thinking that with regular care and maintenance this wouldn't be necessary.  Please share your recommendations. Thanks.

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Offline Stev-o

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Re: Remove finish on motor case?
« Reply #1 on: September 25, 2017, 05:56:26 PM »
The finish on the case is paint. If stock finish is desired, sand, clean and repaint with VHT aluminum, it will look like new.
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Offline Don R

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Re: Remove finish on motor case?
« Reply #2 on: September 25, 2017, 07:54:17 PM »
 I like them naked.
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Offline calj737

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Re: Remove finish on motor case?
« Reply #3 on: September 25, 2017, 10:40:10 PM »
You are correct the paint is to prevent oxidation. Left untreated, it will oxidize (how badly depends upon your care and weather conditions) and be rather difficult to maintain. A light coat of paint works wonders. Scuff off the loose stuff, spray a light primer, then top coat with VHT. Easy enough to do in the frame with some care and masking.
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Offline SOHC4 Cafe Racer Fan

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Re: Remove finish on motor case?
« Reply #4 on: September 26, 2017, 09:39:15 AM »
One more step on painting -- clean the surfaces thoroughly before priming and painting.  Wipe down twice with acetone. 
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1975 CB550F1 frame/CB650 engine hybrid "The Hot Mess" (http://forums.sohc4.net/index.php/topic,150220.0.html)
2008 Triumph Thruxton (http://forums.sohc4.net/index.php/topic,190956.0.html)
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"There are some things nobody needs in this world, and a bright-red, hunch-back, warp-speed 900cc cafe racer is one of them — but I want one anyway, and on some days I actually believe I need one.... Being shot out of a cannon will always be better than being squeezed out of a tube. That is why God made fast motorcycles, Bubba." Hunter S. Thompson, Song of the Sausage Creature, Cycle World, March 1995.  (http://www.latexnet.org/~csmith/sausage.html and https://magazine.cycleworld.com/article/1995/3/1/song-of-the-sausage-creature)

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2005 RVT1000RR RC51-SP2 "El Diablo" - Sold
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Offline Don R

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Re: Remove finish on motor case?
« Reply #5 on: September 26, 2017, 09:05:02 PM »
 Got the paint hot and cured before the carbs leak.
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Offline SOHC4 Cafe Racer Fan

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Re: Remove finish on motor case?
« Reply #6 on: September 27, 2017, 08:35:47 AM »
Got the paint hot and cured before the carbs leak.

It is key to try to get the paint to cure ASAP, so it becomes more durable and stain resistant.
1975 CB550K1 "Blue" Stockish Restomod (http://forums.sohc4.net/index.php?topic=135005.0)
1975 CB550F1 frame/CB650 engine hybrid "The Hot Mess" (http://forums.sohc4.net/index.php/topic,150220.0.html)
2008 Triumph Thruxton (http://forums.sohc4.net/index.php/topic,190956.0.html)
2014 MV Agusta Brutale Dragster 800
2015 Yamaha FZ-09 (http://forums.sohc4.net/index.php/topic,186861.0.html)

"There are some things nobody needs in this world, and a bright-red, hunch-back, warp-speed 900cc cafe racer is one of them — but I want one anyway, and on some days I actually believe I need one.... Being shot out of a cannon will always be better than being squeezed out of a tube. That is why God made fast motorcycles, Bubba." Hunter S. Thompson, Song of the Sausage Creature, Cycle World, March 1995.  (http://www.latexnet.org/~csmith/sausage.html and https://magazine.cycleworld.com/article/1995/3/1/song-of-the-sausage-creature)

Sold/Emeritus
1973 CB750K2 "Bionic Mongrel" (http://forums.sohc4.net/index.php?topic=132734.0) - Sold
1977 CB750K7 "Nine Lives" Restomod (http://forums.sohc4.net/index.php?topic=50490.0) - Sold
2005 RVT1000RR RC51-SP2 "El Diablo" - Sold
2016+ Triumph Thruxton 1200 R (http://forums.sohc4.net/index.php/topic,170198.0.html) - Sold

Offline RAFster122s

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Re: Remove finish on motor case?
« Reply #7 on: September 27, 2017, 12:01:46 PM »
The aluminum will not oxidize in a consistent manner leaving you with a multicolored dull light grey to a almost black in some areas.  The alloy used is part of the reason for this. Unless you are going to polish them and keep them maintained that way, then paint them.  If you are near the sea, then do not try to have polished parts that are not well protected or maintained.
My $0.02
David- back in the desert SW!

Offline RAFster122s

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Re: Remove finish on motor case?
« Reply #8 on: September 27, 2017, 12:05:11 PM »
Also, any oxidation will be accelerated by moisture and dirt.

The oxidation will build up in many areas and that oxidation will collect dirt and look grungy.
It is not easy to remove heavy oxidation.
David- back in the desert SW!