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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: belfert on February 20, 2007, 05:21:53 PM

Title: Do buses normally use clear coat over the paint?
Post by: belfert on February 20, 2007, 05:21:53 PM
Do you guys have clear coat over the paint on your buses? 

My friends and I can paint the bus with automotive paint okay, but none of my friends has any idea how to spray clear coat.  I will be building a new bus garage this summer and can use that to paint the bus inside.  Right now I'm not sure I'll have to time to paint the bus this summer.  It is more likely to be next winter's project since the garage will be heated.

Brian Elfert
Title: Re: Do buses normally use clear coat over the paint?
Post by: tekebird on February 20, 2007, 06:01:20 PM
most buses are painted with higher end paint like Imeron (sp?)  It is very durable but also very hazzardous ( read: Full Body suit and resperator.

My 04 was painteted with it in 1978 and still looks great.....and has lived outside most of it's life since the paint job
Title: Re: Do buses normally use clear coat over the paint?
Post by: NJT5047 on February 20, 2007, 06:16:22 PM
Mine's clear coated.  PPG automotive system.  
Clear coat is simple...just like painting it again, with invisible paint.  Problem with most clear coat finishes is that the clear must be shot about 20 minutes after the color coat.  We divided up the sides and roof to get the areas covered within the time limits.   You could do the same with couple of painters following each other.  
You'll need a support crew to get the bus painted due to mixing required for base coat-clear coat sytems.  And a lot of air.
PPG and Martin Senior have websites that describe the process.  
The paint is toxic so be careful.  Most automotive paint systems are toxic.
My clear didn't flow out like it could...still, it has proven pretty durable. 
Tree branches are hell on the sides....clear coat does a good job of protecting the finish. 
JR
Title: Re: Do buses normally use clear coat over the paint?
Post by: JimC on February 20, 2007, 06:17:37 PM
If your friends can ( or have ) spray enamel successfully they should be able to spray the clear coats. The difference is that the base goes on very dry, it is very forgiving, the clear then goes over that with a heavy coat or two.

Start checking some of the paint Bulletin boards out, autobodystore.com comes to mind. Also buy your paint from a high traffic auto paint supplier and pick the brain of the counter help about what tip to use in the gun for the base and then for the clear.

Like already said, the paint is TOXIC, a full fresh air suit should be worn. If you have not painted large machines before, you may be money ahead to contact some of the body shops in your area and find someone that will come to your shop and spray it after you do the prep work.

Major cost of a paint job is in the labor to prep it properly, second would be the cost of the paint materials, the third would be the labor to just shoot it. If you are going to do the firt two properly, why not pay a pro for a day to spray it right to make the work look good.

Good luck
JimCallaghan
Title: Re: Do buses normally use clear coat over the paint?
Post by: NJT5047 on February 20, 2007, 06:37:02 PM
Jim jogged a thought when he sez paint it in your shop...in addition to being toxic, paint fumes are downright explosive.   Wait for a nice day and open up the place.  The small amount of dust won't be noticeable on a bus.   Be sure that no water heaters, or open flame....you get the picture.
FWIW, I spent $1500 bucks at jobber, for the all of the material to paint my bus.   Paid a pro (semi pro?) another $1500 to help prep and shoot the paint.  Started with him doing all the prep...but that wasn't going too well.  I had to do a good bit of the prep work.  This is tedious.  Painting is the easy part. 
You want to get a good job the first time...modern paint is hard and about impossible to remove if you really screw it up.  Have to sand it or strip it off.  Maybe plastic bead or walnut shell blast?  And sanding is about impossible on riveted sides like my MC9. 
Unlike enamel paints,  the new paints are applied at low pressures with HVLP guns and the loss to over spray is minimal.  You could paint your coach with two gallons of color coat...plus 3 gallons of clear.  Keep in mind that the paint volume is almost doubled with other components. Modern paint goes a long way. 
JR 

Title: Re: Do buses normally use clear coat over the paint?
Post by: Dreamscape on February 20, 2007, 08:18:42 PM
When spraying your clear coat, mix a little of the base color in with the clear to give it some depth. You might be suprised how good it will look.

Good Luck with your project. I also would like to paint our Eagle myself and will be interested in your result. I have never painted a vehicle so large.

Paul
Title: Re: Do buses normally use clear coat over the paint?
Post by: Jeremy on February 21, 2007, 02:31:01 AM
The colour you choose will determine whether you have to use a base coat / clear coat system. If I was using a solid colour I would consider using a two-pack paint on the bus, which has much greater durability than regular car paint, but is more expensive. Two pack paint is as tough as fibreglass gelcoat, but likes to be applied to a firm substrate - if the panels of your bus flex then two-pack paint may crack and flake. If you are using a metalic colour then it has to be a base coat / clear coat system, although you can also use the clear coat to give extra shine & protection on regular single-pack paints (check with the supplier for chemical compatibility first though - there's nothing more heart-rending than spraying a coat of lacquer as a final touch to your fantastic new paint scheme, only to see the whole lot start to bubble and react). Lacquers are easy to apply, but sometimes have a habit of 'lifting' after having been exposed to sun for a few years - I don't know why this happens (it occurs on 'professional' paint jobs too), but I would want to do some research on how to prevent it before doing a big job like a bus.

Lastly, all the safety advice already given should be taken very seriously, especially the air-fed mask (which requires a second compressor and thus more cost). You might consider using water-based paints though, which are less harmful and much easier to use all-round. I don't know about America, but water-based paints have been used for many years here in marine applications, and from July 2007 they become mandatory for all spray paints - you simply won't be able to buy solvent-based paints anymore

Jeremy
Title: Re: Do buses normally use clear coat over the paint?
Post by: jjrbus on February 21, 2007, 07:59:14 AM
Mine is painted with polyureathane, no clear coat. It has been mentioned on here to do the prep work yourself. This is the expensive part of the paint job and you will probobly do a better job, becuse its yours and you care more. Then have it painted by a pro. Really the best way to go. While Macco and Ben ?? and these 24 hour places have a bad rap. But if you check a few you can find a man that has been painting 5 cars a day for years and is a true expert! A neophyte could make a real mess out of something as big as a bus!! Just my opinion, Ive seen some really nice first time paint jobs.
Title: Re: Do buses normally use clear coat over the paint?
Post by: belfert on February 21, 2007, 08:41:11 AM
It looks like Acrylic Enamel might be a good option for a paint that doesn't require a clear coat.  Most of the base coat/clear coat systems I found actually require the base coat to be dry before the clearcoat goes on so time isn't as big a deal if I do go with clearcoat.

I am looking for a paint job that just looks halfway decent and not like a rattle can job.  It doesn't have to shine like a car at Barrett-Jackson.

I would probably buy a fresh air respirator for the persons spraying.  I figure total costs including prep materials, paint, respirator system, and sprayer would be around $1500.  Still a lot less than a pro shop.

Brian Elfert
Title: Re: Do buses normally use clear coat over the paint?
Post by: Jeremy on February 21, 2007, 09:35:59 AM
Quote from: belfert on February 21, 2007, 08:41:11 AM
It looks like Acrylic Enamel might be a good option for a paint that doesn't require a clear coat.  Most of the base coat/clear coat systems I found actually require the base coat to be dry before the clearcoat goes on so time isn't as big a deal if I do go with clearcoat.

I am looking for a paint job that just looks halfway decent and not like a rattle can job.  It doesn't have to shine like a car at Barrett-Jackson.

I would probably buy a fresh air respirator for the persons spraying.  I figure total costs including prep materials, paint, respirator system, and sprayer would be around $1500.  Still a lot less than a pro shop.

Brian Elfert

The base coat is actually 'dry' almost as soon as it hits the surface - by themselves the base coats give a quite soft and 'matt' finish that is quite unlike a regular paint which goes on 'wet and shiny' and takes a while to dry. I'm not really sure what happens if you delay the application of the clear coat too long (ie. more than 15-20 minutes), but I expect the adhesion of the clear coat would be reduced.

Also - check the suitability of the respirator you buy with the chemicals being used - many paints require masks / suits that have clean, fresh air pumped to them from outside - a mask which merely filters air taken from inside the paint booth before it is breathed by the user cannot be guarenteed to prevent the paint cyanide from reaching your lungs. As I mentioned before a second compressor is usually used for the air-fed mask, and it has to be a big compressor at that as a lot of air volume (CFM) is required, albeit at a low pressure. I actually modified an air pump I already had to supply my mask, which required a bit of messing about with hose couplings but was a lot cheaper than buying the 'proper' compressor that the mask required.

Jeremy
Title: Re: Do buses normally use clear coat over the paint?
Post by: Dallas on February 21, 2007, 10:07:40 AM
Quote from: Jeremy on February 21, 2007, 09:35:59 AM


The base coat is actually 'dry' almost as soon as it hits the surface - by themselves the base coats give a quite soft and 'matt' finish that is quite unlike a regular paint which goes on 'wet and shiny' and takes a while to dry. I'm not really sure what happens if you delay the application of the clear coat too long (ie. more than 15-20 minutes), but I expect the adhesion of the clear coat would be reduced.

Also - check the suitability of the respirator you buy with the chemicals being used - many paints require masks / suits that have clean, fresh air pumped to them from outside - a mask which merely filters air taken from inside the paint booth before it is breathed by the user cannot be guarenteed to prevent the paint cyanide from reaching your lungs. As I mentioned before a second compressor is usually used for the air-fed mask, and it has to be a big compressor at that as a lot of air volume (CFM) is required, albeit at a low pressure. I actually modified an air pump I already had to supply my mask, which required a bit of messing about with hose couplings but was a lot cheaper than buying the 'proper' compressor that the mask required.

Jeremy

Jeremy,

Around here I've seen painters and spray foam applicators use vacuum cleaners with the hose put on the exhaust side and a filter put across the intake.
Using a long, light weight hose attached to the regular hose lets them move around hither and yon, painting and applicating to they're little hearts content.
Most of the ones I've seen have used Kirby upright vacuums or old Electrolux canister vacuums.

I hope this helps,

Dallas
Title: Re: Do buses normally use clear coat over the paint?
Post by: belfert on February 21, 2007, 10:43:54 AM
Quote from: Jeremy on February 21, 2007, 09:35:59 AM
Also - check the suitability of the respirator you buy with the chemicals being used - many paints require masks / suits that have clean, fresh air pumped to them from outside - a mask which merely filters air taken from inside the paint booth before it is breathed by the user cannot be guarenteed to prevent the paint cyanide from reaching your lungs. As I mentioned before a second compressor is usually used for the air-fed mask, and it has to be a big compressor at that as a lot of air volume (CFM) is required, albeit at a low pressure. I actually modified an air pump I already had to supply my mask, which required a bit of messing about with hose couplings but was a lot cheaper than buying the 'proper' compressor that the mask required.

Th fresh air respirator I'm talking about is a respirator that has fresh air pumped in from a source outside the room.  I found a system for $500 that doesn't appear to require an air compressor.  It has two hoses and masks, but is rated for hobby use.


Brian
Title: Re: Do buses normally use clear coat over the paint?
Post by: Jeremy on February 21, 2007, 10:56:34 AM
Quote from: Dallas on February 21, 2007, 10:07:40 AM

Jeremy,

Around here I've seen painters and spray foam applicators use vacuum cleaners with the hose put on the exhaust side and a filter put across the intake.
Using a long, light weight hose attached to the regular hose lets them move around hither and yon, painting and applicating to they're little hearts content.
Most of the ones I've seen have used Kirby upright vacuums or old Electrolux canister vacuums.

I hope this helps,

Dallas

Yep, that's pretty much identical to what I did. I did find that the long 'curly' airhose I bought specially for the mask was too narrow and restricted the airflow to much (it was obviously designed to flow less volume and more pressure). Instead I reverted to a much thicker hose that I strap alongside the spray gun's hose - that way you only have to watch out for one thing dragging behind you and potentially touching your freshly painted surface.

Jeremy
Title: Re: Do buses normally use clear coat over the paint?
Post by: Jeremy on February 21, 2007, 11:24:05 AM
Quote from: belfert on February 21, 2007, 10:43:54 AM
Th fresh air respirator I'm talking about is a respirator that has fresh air pumped in from a source outside the room.  I found a system for $500 that doesn't appear to require an air compressor.  It has two hoses and masks, but is rated for hobby use.


Brian

Sounds like just what you want - I'd be looking to hire one though, or make you own system rather than spending $500 for a one-off job

Jeremy
Title: Re: Do buses normally use clear coat over the paint?
Post by: Ross on February 22, 2007, 05:27:57 AM
Nason Fullthane is a polyurethane that comes in metalic colors.  If you want to spray metalics, you better know how to do it or you'll end up with paths of differing metalic density.  You can clear over Fullthane if you want, but it's not nessessary.  Fullthane flashes off a little slower than some of the other single part urethanes which gives you a little more time.  The added time helps to reduce dry spots between overlaps.  If the paint flashes off too fast and/or you go too slow, you'll end up with a dry stripe at every overlap.  I did my bus in Fullthane 4 years ago.  It has never been waxed and it looks as good as the day I did it.  I've seen some very nice backyard paint jobs....and some pro jobs that I personally never would have accepted, especially for what they charge. 

Ross