Any words of wisdom regarding frame and engine painting?

[paul25g]

Hi all,

I’m getting ready to repaint my 175DTs frame and engine.  I’m new to this so have a few questions.

I plan on sandblasting the frame and using walnut shells to blast the engine case.  I have a few questions in regards to the type and amount of paints to use.

First of all, in regards to the frame and engine, would it be better to use laquer or enamel and how many coats?

Would the engine need a high temp paint?

After priming and top coating the frame, should I spray some clear coat?

Would the engine case need primed before a top coat?  Would the engine case need a clear coat after the top coat?

Any other suggestions or words of wisdom in regards to painting?

Thanks in advance!

Paul

[duckman86]

I'm afraid i can't help you too much but i used hi temp 500 F on my engine and it works great. I wouldn't recommend using stuff not rated for heat as i have done this in the past and it always blackens... burns off and burns into the metal. let me know how it go's I'm thinking of repainting my 90

[rocketman]

So many avenues...I like the idea of media blasting vs sand even for the frame. Especially soda,it does not abrade the surface. It won't eat heavy rust out of pitted areas,you will need sand,etc.for that. I would probably opt for soda for any stripping of painted aluminum or magnesium because of the abrasion factor. For the frame,laquer paint is "old school" and when done right,looks great. It's not nearly as durable or chip resistant as enamel or a two part urethane,and tends to die out faster with metalics in particular. It requires a bit more maintanence as well. If your not concerned with absolute originality/concourse restoration,I would use a good automotive enamel or urethane. You can't beat the base coat/clear coat systems for shine and depth,and once finished and polished they pretty much stay that way. I personally prefer Dupont,but there are many quality manufacturers. On the lower end,aerosols have come leaps and bounds in the last few years. Duplicolor has a top notch line of aerosols that you can clear coat if you choose,and are actually of a quality that allows you to rub (polish) the finish. I believe it is a laquer based product. I get away with non heat paint on the engine cases,but normally use heat paint for the cylinder and head. I like VHT for their flat aluminum. For black heat,Rustolium bar-b-que black. The aerosol is very flat and doesnt work as well as applying it from the pint can. You can spray,brush or roll it. I use Sem trim black 39143 aerosol for all the semi gloss stuff and consequently,I painted a complete Honda XR600 motor with the Sem,including the cylinder and head,and it has not yet burned off anywhere. Tuff stuff. Sem also makes some high quality aluminum colors in aerosols and thier rust shield line. For your tank,consider a professional shop. Unless you are equipped,the materials are expensive and usually have to be purchased in such quantities that it drives the cost of refinishing small parts to extremes. A pint,(usually the smallest mix you can buy over the counter),of red family pearl/metalic can run you on the high end $90.+. Ouch! Then you need a trunk load of staples to apply and finish it. As for priming aluminum,etc.,reference the paint system you choose to use for thier reccomendations. Some finishes are self etching and won't require any.  Have fun!  Mark.

[paul25g]

Thanks for all the guidance so far....will probably get started on this in the next week or two...weather depending.

So it sounds like walnut shells might even be too abrasive for the engine?  Do walnut shells abrade the surface at all?  I take it that soda would do the least damage.

Also, if the heads & cylinders are media blasted to clean off the corrosion....would they then need to be top coated with an aluminum paint or could they be left bare?  In other words were the heads & cylinders originally painted or not?

I know the tank, side covers, tool box, fork & shock uppers and headlight are best left to professionals, but I figure I can take care of the engine and frame on my own.

Thanks again guys!

Paul

[duckman86]

I don't believe the cylinder and heads were painted if they came stock aluminum. But I'm going off information based mainly off the smaller sized bikes 90 and lower. I've seen a 90 sport where the aluminum cylinder was unpainted and then my bs came with iron cylinder and was painted black with a unpainted aluminum head.

[rocketman]

 I guess I would have to say that the raw aluminum parts like the cylinders and heads condition after cleaning sort of determines what steps need to be taken to improve or maintain them. Since its real hard sometimes to return the brightness of cleaned up parts to the factory look of freshly cast aluminum,I usually opt to paint them. Even when you do get a nice enough finish to leave alone,it seems to get grungy faster and is harder to clean back up than if it were painted. The other alternative leads you to time and money to brighten and polish. The polished aluminum parts,like center cases and carb covers on a lot of the Bridgestones,need to be polished for a factory look. If you want,any of this stuff can be painted to conceal repairs or blackened surfaces that won't polish,or just to suit your taste. Walnut shells,I've heard of but never used myself. I can only attest to the beautiful polished surface left after soda blasting. If your stripping paint from a polished aluminum case with soda,when your done you have a polished surface still. Where sheetmetal panels are spot welded together,the blueing of the original weld will still be there. You will be amazed.

[paul25g]

I've found a place locally that sells the soda blasting media.  Can this be used by running it through a standard air compressor & sand blasting gun?  Thanks!

[rocketman]

 Soda is a very soft medium and has special requirements to use it. I don't think you'll have much luck trying to use it through conventional means. It's usually mixed at the blast tip. There are a few economical soda/multi media blasters and cabinets available on the market suitable for home or light shop use,but know also that proffessional units get expensive. Media blasting in general requires very dry compressed air. This is particularly true with soda and can potentially cost you some extra coin in equipment (air cooler/drier). There are also wet systems available that dampen the dust cloud created by the soda,and water pressure systems that mix the soda directly into the water jet. It's just a matter of how much you want to spend! I would check with local shops/auto restorers in your area,they should be able to point you toward someone who's already equipped. Local prices seam to be @ $150.00/hour. That should take care of pretty near your whole bike.

[paul25g]

Guys,

Just an update.  Finally decided to go with Powdercoating on my frame, swingarm, center stand, kick stand, etc.  Did a search and found a place in town that does this.  These guys did a great job and at a price that I couldn't have gotten it painted for (I did the sandblasting to keep the cost down, but they can do this too).  I'd highly recommend them.  They're located in Greenville, Ohio (west-central Ohio).  Called DCF Powdercoating.  It's a small operation but they did a great job.  If anyone's interested in their contact info, let me know.  Thanks!

Paul