Prepping for Paint.

[Gimpdiggity]

Hi everyone.

I've owned bikes for quite a while, however, this is going to be the first time that I've ever actually tried to paint anything other than just slapping some touch up paint on a door ding.

I'm planning on just rattle canning it for now, but I want to get the prep part down.

When I'm sanding the paint, is there any reason to go all the way to bare metal?? Or is it best just to scuff up the paint that is already on the parts that need to be painted?? I'm of course referring to the tank when I talk about sanding down to bare metal. The plastic parts I know those can only be sanded, but obviously not down to metal.


Thanks!!

 

[Gimpdiggity]

Forgot to add this...

I'm not going for anything super spectacular here, either. I'm just doing it because the paint that's on it is chipped, faded, and downright not good.

I'm not that worried about if the bike doesn't turn out to look like a million bucks. I'm fine with it being functional and not that pretty.

 

[GQROD]

Just scuffing is usually fine.

Spray primer this will show all the flaws.

Fill dents and scratches with filler or glazing putty.

Spray primer

Sand it with progressively finer paper from 400 to 800

Use wax and grease remover to clean

Tack rag to get off fine dust

Then spray your color coat, sand with 1000 to 1500 between color coats then spray clear, it should look prefessional with a little patience and elbow grease.

 

[Gimpdiggity]

Cool. Thanks!!

I won't need to worry too much about sanding the top coat, because the top coat is going to be truck bed liner. I've done another bike with bed liner and absolutely loved the way it turned out, so I'm going to be trying it on this.

I mentioned rattle cans because that's what I have for primer.

Thanks again!!!

 

[GQROD]

No problem, just remember the rattle can clear coat is not gsoline proof and let it cure for 60 days before you buff it out if you do paint in the future then keep it waxed.

Do a search there was another member who did this and it looked showroom it was a black tank.

Post pics when you are done so the rest of us can be proud of your work!

 

[spyug]

Ok I'm not a pro painter but have been painting things for years. I'll tell you all I know

First and foremost the paint job will only be as good as the prep.. So time spent getting the surfaces clean and smooth will be wll worth it.

It is not necessary to go back to metal as long as the surface is smooth with no nicks or gouges. Anything like that should be filled with a scratch filler and feathered out so that running your fingers over it with eyes closed and you won't feel any irregularities.

Use wet and dry paper to sand. Start with 320 for a quick cut then move up to 600 to rmove scratches. Use lots of water with a hint of dish soap for lubricant. Wipe down the surface with mineral spirits (paint thinner) and allow to dry before going to paint.

Use a good quality primer and light colours are best (grey or tan). I assume you know how to use a spray bomb but just to remind you several light coats are better than heavy. Lightly sand and wipe down before surface paint.

When going to the paint again light coats and you should sand between coats with 1000 or 1500 grit to get a good bond. If you are going to clear coat make sure the clear is compatable with the base paint. Again use the 1000 on the base and wipe and dry before the clear.Do as many clear coats as you like for the deeper shine (2 are usually enough).

Now a note on clear. Canned clear like Duplicolor is not gas resistant no matter what they tell you. Urethanes (2part automotive) are the only paints that will slough off gas. Check with your local automotive paint supplier as some can provide you with urethane clear in a can.

You can get nice finishes with cans but 2 part urethanes are better but require a bit of an outlay for equipment. Having said that however, you can get small electric compressors and HVLP guns for around $100.

In all cases, when spraying paint a) get and wear a proper paint rated mask b) spray only in a well ventilated area and c) don't spray anywhere near flame or even spark. Think safety all the time and that means keep your kids and pets out of the way too.

Hope this helps a bit. If you have any doubts or other questiosn pm me.

Good luck with it and show us what you produce.
Cheers,
Spyug

PS I might be the guy Gcrod is referring to. I did my GS in black rattle can and shot the urethane clearcoat with my HVLP

 

[Nessism]

For bedliner paint I would just scuff the stock paint with 400 or so and shoot the bedliner right on top. No primer unless you have bare metal showing or bondo from a repair. The bed liner paint is super thick so no need for fancy metal prep.

 

[Gimpdiggity]

For bedliner paint I would just scuff the stock paint with 400 or so and shoot the bedliner right on top. No primer unless you have bare metal showing or bondo from a repair. The bed liner paint is super thick so no need for fancy metal prep.

Yah, I have to go down a bit for a few small dents.

I think after I Bondo them up, I'll just scuff it up then throw the bedliner down.

 

[Supavert]

Spyug,

That paint job looks real nice. Great job:clap:

Peace, Supavert

 

[rustybronco]

Hi everyone.

I'm planning on just rattle canning it for now, but I want to get the prep part down.

You can get nice finishes with cans but 2 part urethanes are better but require a bit of an outlay for equipment. Having said that however, you can get small electric compressors and HVLP guns for around $100.

In all cases, when spraying paint a) get and wear a proper paint rated mask b) spray only in a well ventilated area and c) don't spray anywhere near flame or even spark. Think safety all the time and that means keep your kids and pets out of the way too.

If you chance your mind about the "for now part", bring the parts over...

I've got a few guns, a small compressor and a mask. I have filler, the clear and hardener, you will need the "urethane base coat".

 

[GQROD]

If you chance your mind about the "for now part", bring the parts over...

I've got a few guns, a small compressor and a mask. I have filler, the clear and hardener, you will need the "urethane base coat".

What size compresor do you have ?

i'm shopping for one right now to shoot some 2k urethane on a hard bag project i've been working for my bike.

Also a bit of waring on 2k urethane, it's toxic stuff and can cause a host of health problems if you don't wear the correct safety equipment everyone, definetly not a first timer type of paint.

 

[rustybronco]

What size compresor do you have ?

i'm shopping for one right now to shoot some 2k urethane on a hard bag project i've been working for my bike.

Also a bit of waring on 2k urethane, it's toxic stuff and can cause a host of health problems if you don't wear the correct safety equipment everyone, definetly not a first timer type of paint.

1 h.p two stage 110v. (I painted the Honda with it and my hvlp. it's a little slow to recover when spraying, but it was easily do-able.)
2 h.p two stage 220v.

 

[GQROD]

1 h.p two stage 110v. (I painted the Honda with it and my hvlp. it's a little slow to recover when spraying, but it was easily do-able.)
2 h.p two stage 220v.

I hae seen the 89.99 hvlp spray gun/compressor but i wasn't convinced it would do a good job spraying urethane.

How many gallons are they both and how much CFM are they rated at 40 PSI?

I was considering a 220volt 21 gallon unit with over 8 cfm at 40 psi, some hvlp guns i have seen are rated at 6 cfm.

How much time were you able to spray before you had to wait for the tank to fill up?

I'm planning on painting my car and my bike towards the end of spring and wanted a compressor mainly for spraying. I can't see getting the 60 or 80 gallon units though better for such small projects.

 

[rustybronco]

I hae seen the 89.99 hvlp spray gun/compressor but i wasn't convinced it would do a good job spraying urethane.

How many gallons are they both and how much CFM are they rated at 40 PSI?

I was considering a 220volt 21 gallon unit with over 8 cfm at 40 psi, some hvlp guns i have seen are rated at 6 cfm.

How much time were you able to spray before you had to wait for the tank to fill up?

I'm planning on painting my car and my bike towards the end of spring and wanted a compressor mainly for spraying. I can't see getting the 60 or 80 gallon units though better for such small projects.

quite a few questions you have.
I can obtain the numbers for you on the 2 hp compressor, off hand I don't recall exactly. (IIRC 20 gallon)

with the 1 hp 12 gallon and 6.9 cfm @ 40 psi, which I used with a 9.5 cfm hvlp @ 25 'ish psi.
see...http://www.thegsresources.com/_forum/showthread.php?p=536187#post536187

continuous spray time 1-1/2 minutes?, it worked fine for the small pieces I painted, but to do a car with it... NO!

I have painted completes with the 2hp and a gravity gun.
but please keep in mind they are old cast iron 2 stage compressors, not the pancake style.

 

[GQROD]

quite a few questions you have.
I can obtain the numbers for you on the 2 hp compressor, off hand I don't recall exactly. (IIRC 20 gallon)

with the 1 hp 12 gallon and 6.8? cfm @ 40 psi, which I used with a 9.5 cfm hvlp @ 25 'ish psi.
see...http://www.thegsresources.com/_forum/showthread.php?p=536187#post536187

continuous spray time 1-1/2 minutes?, it worked fine for the small pieces I painted, but to do a car with it... NO!

I have painted completes with the 2hp and a gravity gun.
but please keep in mind they are old cast iron 2 stage compressors, not the pancake style.

Thanks for the advice,

So with a siphon gun and a " 21 gallon 3hp compressor 220v rated for continuous use " should be fine to paint a car one panel at a time even though it means stopping once in awile? I don't think this unit is two stage, it's a single piston compressor.

 

[rustybronco]

Thanks for the advice,

So with a siphon gun and a " 21 gallon 3hp compressor 220v rated for continuous use " should be fine to paint a car one panel at a time even though it means stopping once in awile? I don't think this unit is two stage, it's a single piston compressor.

Single stage.

and I ask you, what are the requirements of the gun and what are the spec's of the compressor.

you could paint a complete with what I have, if you wanted to do it panel by panel and put your mind to it. I shot a 3x4 ft hood and a front end cover with it.

 

[GQROD]

Single stage.

and I ask you, what are the requirements of the gun and what are the spec's of the compressor.

you could paint a complete with what I have, if you wanted to do it panel by panel and put your mind to it. I shot a 3x4 ft hood and a front end cover with it.

Great link and review of the hvlp gun, you answered my question!

The gun is rated at 2 cfm, however i read you should multiply the gun requirements by 4 for spraying or DA sanders ( i won't be using a DA )

So i came up with 8 cfm needed by the gun, and the compressor is 8.8 CFM at 40 PSI.

I could buy a HVLP that is rated at 6 FM without multipliying the needed CFM, ( these are matched to the Husky brand compressor single stage 30 gallon 2-3 hp, 115 volt that is rated at 6.5 CFM at 40 psi )

i just wanted to make sure all this made sense before i buy the compressor.

Thanks and sorry for the thread hijack.

 

[spyug]

One thing to note about spray equipment. Although the gun maybe HVLP ( High volume/low pressure) and call for spraying paint at 20 psi or so you need to have compressor outlet pressure set as high as you can 80/90psi or higher. Pressure will drop right off in the 6 feet from tank to gun. Trust me on this.

Urethane is nasty stuff so don't scrimp on the mask and it is not a bad idea to wear goggles and have fresh air moving (i.e. a fan).

Once you get the hang of HVLP and compressor you are hooked.

Cheers all,
Spyug.

 

[GQROD]

One thing to note about spray equipment. Although the gun maybe HVLP ( High volume/low pressure) and call for spraying paint at 20 psi or so you need to have compressor outlet pressure set as high as you can 80/90psi or higher. Pressure will drop right off in the 6 feet from tank to gun. Trust me on this.

Urethane is nasty stuff so don't scrimp on the mask and it is not a bad idea to wear goggles and have fresh air moving (i.e. a fan).

Once you get the hang of HVLP and compressor you are hooked.

Cheers all,
Spyug.

Yes you are right about how nasty that stuff is, i'll be painting outdoors with the proper equipment, coveralls, gloves, sock, etc.

I'll most likely be going with black pipe to route the air towards the work area then a 20ft hose max to the gun including the oil/water/air filter. The black pipe will cool the air and be angles to draing the water towards the tank.

Thanks again for the advice!