Sanding Side Covers

[cowboyup3371]

So I'm sanding down an old broken side cover to prep for testing a paint scheme I want to do. It was originally black with some pinstriping on it. I am using 120 grit paper to start with since that's all I have right now and this is where I'm at after 5 mins of sanding. I know I haven't gone far enough yet but I'm wondering what it should look like when I'm done? What color will it look like?



Typically, how long should a good sanding job last?

[cowboyup3371]

This is after about 45 minutes of total sanding time. Most of the striping is gone but I don't see any color change. Top left corner is cracked so I'm not that worried about getting up there.

[81GS750]

I'd take it down to 400 grit paper and try to get the 120 grit scratches out. Just make sure all the old paint is sanded dull, leave no shiny spots. I wouldn't worry about trying to sand off all the old paint though. The plastic on my side covers was black. You'll know when you get to plastic, you will start to see the feathered edge of paint on top and the plastic underneath.

[cowboyup3371]

Okay thanks for the tip. I'm doing schoolwork right now so I'll get back to it tomorrow night with that. I appreciate it.

[81GS750]

Yup, and you may want to spray some primer over it to seal out the old paint and fill the scratches too.

[cowboyup3371]

Planned to. I'm planning on testing out the color idea and see how well a rattle can job will do on it versus the right way (spray gun). I like the idea of the spray gun but am not sure I want to make the investments I'll need (new compressor since mine is too small, gun, etc). I wasn't too happy seeing the cost of using the Army base's equipment and procedures to get in to use it but hey, that's an option I'll keep on considering.

[Nessism]

Hey Scott,

Looks good so far. I'd fix that crack by laying down a fiberglass patch over the cracked area on the inside and laminating it in with epoxy. Try to get some glue inside the crack too. After that you need to move to progressively finer sand paper - 320 or so before primer. I'm not a fan of rattle can paint, but then again I've spent a kings ransom on paint so don't listen to me if you don't have the budget.

[cowboyup3371]

Thanks Ed. This is just an old piece that I don't use on the bike which is why I'm testing on it. The good pieces are still sitting on the bike for the time being until I figure out what I'm doing.

[Nessism]

Thanks Ed. This is just an old piece that I don't use on the bike which is why I'm testing on it. The good pieces are still sitting on the bike for the time being until I figure out what I'm doing.

Scott,

I'd try to use a finer sandpaper next time. And use a sanding block when removing any graphics so you get a nice flat surface. With the coarse paper like you used you will have a lot of sanding still needed to remove the sanding scratches.

Good luck.

[cowboyup3371]

Thank you Ed. I'll do that.

[posplayr]

I know there are a hunderd ways to do this but I like to use an orbital sander with different grits of Sandpaper. I have a couple of Bosch sanders that use teh hook and loop pads. It will even make short work of the tank but since then I've gone to chemical stripping on the tank; much less dust.

Just be careful about sanding off all of tge edge detail. You can build it back up with the primer, but a pain if everything is all rounded off.

http://s449.photobucket.com/albums/qq215/posplayr/GSR/GS750_Tank/GS750_Prep/?albumview=slideshow

I think I also did a right up but cant find it.

There are other brands but the Bosch has been real reliable

http://www.cpotools.com/bosch-random-orbit-sanders/bosch-random-orbit-sanders,default,sc.html?srule=price-low-to-high&start=0&sz=12

I originally bought it to sand and strip exterior french door thresholds

[cowboyup3371]

Hey thanks Pos. So I can use an orbital on the side panels? I ask because a local paint shop guy said to do the sides by hand but that I could use an orbital on the tank (which I will do after the fun last night). Also, is that muriatic acid pretty much the same thing as aircraft stripper?

[81GS750]

He probably didn't want you using a power sander on plastic because you can ruin a side panel in a hurry if you dig too deep or round off the edges. Personally, I'd do it by hand, but thats just the way I am about it. Also, I wouldn't use chemical stripper on plastics. On steel parts fine, but not on plastic. I think there's more to it than muriatic acid. Aircraft stripper is a pretty thick gel, not too expensive either.

[cowboyup3371]

Yea I'm picking some up (the aircraft stripper) on Tuesday since the paint shop didn't have any Saturday due to the holiday and cold weather.

[posplayr]

He probably didn't want you using a power sander on plastic because you can ruin a side panel in a hurry if you dig too deep or round off the edges. Personally, I'd do it by hand, but thats just the way I am about it. Also, I wouldn't use chemical stripper on plastics. On steel parts fine, but not on plastic. I think there's more to it than muriatic acid. Aircraft stripper is a pretty thick gel, not too expensive either.

There is a bit of skill required with any sanding ,so care is warranted regardless of technique.

A 250 grit with the orbital will take off the material without excessive scratching but works best on the flat sections. You just avoid any corners. With metal there are no worries at all.

If there are any concave areas then find something round ,wrap a piece of paper around it and sand that by hand. Above all don't just fold over a piece of paper and sand with it unless you are just going over it lightly. Block sanding if you plan to take off any significant amount of material.

After primer, make sure to sand the same way keeping edges sharp. I then like to do one or two passes over the edges all at once so I know they are uniform and have not been hit 2-7 time.