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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: Supershooter on September 21, 2022, 06:20:34 PM

Title: What’s the best way to prep an engine for paint?
Post by: Supershooter on September 21, 2022, 06:20:34 PM

I’d like to repaint the engine in my K100. Are there any tips or tricks to getting the engine stripped and cleaned in preparation for painting?
I’ve made some progress but am looking for some shortcuts.
Supershooter

Title: Re: What’s the best way to prep an engine for paint?
Post by: frankenduck on September 21, 2022, 08:58:14 PM

Media blasting.

Title: Re: What’s the best way to prep an engine for paint?
Post by: The Mighty Gryphon on September 21, 2022, 09:32:56 PM

If you can't do a media blast, you can do a good cleaning with S100 with a lot of attention to nooks and crannies using sponges, tooth brushes, Q-Tips, and Scotchbrite.  You might have to hit some really greasy spots twice.  S100 kicks a$$ and will get all the grease and oil off.  Follow this with a wipe using rubbing alcohol and a lot of clean paper towels. 

Any aluminum corrosion can be cleaned up with NAPA Aluminum Brightener and Scotchbrite.  follow the direction on the bottle.

Mask and shoot a couple light coats of Etching Primer.  For all those bare aluminum stripes I cut strips of masking tape by putting the tape on a sheet of glass and cutting narrow strips with a new razor blade and a steel straight edge.  You can also see if you can get 3M Fine Line tape in the right width.

A couple thin coats of a black base coat until you have good coverage.  Then pull the masking tape off the lines and shoot a couple coats of 2K rattle can Matte Clear Coat.  Let the clear coat cure for as long as possible before handling it.  I have found that it can take up to a week or more to get really hard in cool weather.   I use USC 3680065 Spray MAX 2K Matte Finish Aerosol Clear Coat.  Not cheap, but it is easy to use and gets good results.

Title: Re: What’s the best way to prep an engine for paint?
Post by: Supershooter on September 21, 2022, 10:15:42 PM

How critical is it to get all of the paint off before, the prime and paint?

Title: Re: What’s the best way to prep an engine for paint?
Post by: The Mighty Gryphon on September 21, 2022, 10:23:41 PM

If it doesn't come off with the S100 washing and 320 scuffing I just prime over the old stuff.  Just make sure the edge sre feathered in so they don't show too much.