Plastic Preperation Steps

Plastic Preperation Steps

Plastic parts are among the most common of paint failures in the industry. Due to the manucturering proces & combined with the surface tension of plastic, adhesion can be difficult in many instances. Here are some tips to getting your paint to stick:

Clean, Clean & Clean Some More

Plastic depends highly on chemical adhesion which also depends on you sucessfully removing the contaminants that remain on the plastic. Mold release agents are the most stubborn. Clean your plastics with soap & water & a good plastic cleaner.

Sanding Pastes

A good sanding paste will also help you acheive a new level of cleanliness. Use them in conjuction with a grey scuff pad. I've heard of some using comet or ajax powdered cleaner in place of them. I wouldn't advise it, but never using it I don't know exactly what I'm missing.

Remove bad primers

Run adhesion & solvent test on your plastics that come pre-primed, Don't just sand and paint! When you paint over garbage, your paint becomes garbage too!

Check your manufacturers directions

Any reputable paint manufacturer will provide clear instructions for painting plastic parts, follow them! They are key steps in achieving the results you are after.

Establishing good practices for plastic refinishing will prevent common failures such as peeling & excessive stone chipping.

Blending Tips & Techniques

Blending Tips & Techniques

With today's colors, blending is proving to be a more challenging job for painters. Color blending is a necessary part of the repair to ensure an undetectable match between panels on your customers vehicle. The only time I consider skipping this step acceptable is on bumpers that have a poor color match to begin with. If your painting a front cover and the back is already dark to the quarter, it can be acceptable to use a slightly darker tint on the front and not blend the fenders. It can depend on the job and what you think is best for your customer.

Give yourself enough room to make the blend

Always know your limits & your colors. If you don't think you have enough room to make the blend, go into the next panel, it will cost you twice as much when you have to redo the job.

Use an orientation coat

an orientation coat will fill in the smallsand scratches and give your base a flatter surface to be blended on. This can make your job much easier. Their are a few different options you can use for your orientation coat. An overreduced clearcoat works well,simply catalyze your clear & reduce it around 9:1. Another option is a transparent tint, usually just a mixing clear in your existing paint system. Some company's offer it as a seperate product only meant for being applied as an orientation coat, any one of these ways will work great.

Another great method for difficult colors is to lay down your orientation coat again before your final blend coat. Apply your blend coat while it is still flashing, this makes your basecoat land without dryspray which can help eliminate a halo.

Don't Crank the Pressure

Ok, this isn't always true, their are some situations where you can bump the pressure to make your blend easier...sometimes chasing away a silver halo this can help. For the most part, the reason I would avoid this is because more often then not you end up having the rest of your panel covered in a fine overspray. You will hear it when you run the tack cloth over it and it will appear as dirt when you apply your clear. If you want your base to go on dryer I'd advise increasing your gun distance.

Injection Method

This is pretty simple, just make your base more transparent on your blending coats. You can add some clear basecoat (binder) from your paint line to make it easier to blend out. You should try not to exceed a ratio of 1:1 & remember to reduce your binder accordingly. Avoid over-reducing your paint for transparency as it can lead to problems.

Reverse Blend

This technique is now for everybody but it is very effective when utilzed correctly. What you will do is spray your first coat as your blend, fan it out as you normally would. Bring each subsequent coat inside a little bit more until you've acheived hiding. The theory behind it is that your never painting over the previous coat's overspray, each coat lands on a perfectly smooth surface.

Drop Coat

Lowering your air pressure for your final coat is another way to combat difficult colors. The basic idea again is that your paint lands wet and you don't end up with a dry edge that reflects the metallics differently causing a visable blend. With polyester based paints you can drop your pressure even lower and get a really good drop coat on, just keep in mind the drop coat will darken your color, certain silvers and golds this isn't the best idea.

These are a few simple strategies used to make blending easier, other ideas that are sometimes overlooked is color match and equiptment settings. Always make sure your using recommended spray equiptment and ensure that the color your spraying is going to be a blendable match before you try it on your vehicle. Spray out cards only take a few minutes and can sometimes save a few hours!

Different Types of Paint

Different Paint Types

Singlestage - in this paint the color pigment is added to the urethane clearcoat and applied in one step. Singlestage paints do not provide as much protection from the suns UV light which can breakdown the paint pigments. Having clearcoat only on the top provides better protection and holdout. This is a common choice for fleet vehicles and economical jobs. Singlestages can come in both metallic and solid colors, however solid colors are a much more common choice as using a metallic singlestage can limit repair options such as polishibility.

Base / Clear - this the the most common choice of paint used in the industry today. It is a two step process where the bascoat is applied to the surface & followed by a urethane clearcoat on top of it. This how most vehicles are painted from the factory as well as being refinished. These can be solid colors or contain metallics & pearls.

Three Stage/Tri-coat - This process is similar to base/clear. This is only used with pearlescent colors. A solid basecoat is painted on first, then followed by a coat of a pearlescent. This gives the effect that the pearls are sitting on top of the color. It is followed by a clearcoat for shine and protection. This is used sometimes from the factory.

Candies - This is a unique paint jobs that pretty well only exists in custom painting. It is accomplished by spraying a metallic color first, then followed by a transparent solid color. The effect is the metallics reflect through the solid color on top and produce a high sparkle effect.

Metallics vs Pearls

Metallics - these are flakes of aluminum that reflect light. They will compliment the color they are added to and provide a sparkle appearance. They come in different shapes and sizes that will alter the way they appear.

Pearls - these are flakes from the mica mineral. Modern mica's are actually synthetic and not mined but still produce the same effect. They are also coated with another mineral that will give the mica a color. The mica flakes are able to provide a seperate color of the paint, the color depends on the mineral they are coated with. Mica flakes allow light to pass through them and a visible color is produced.

Waterborne vs Solvent

The only difference between the two is the delivery method. The pigment is transfered to the surface using either of the two. They each present different strenghts and weakness's for the refinisher but their is not much difference in the quality they produce. Their are a few waterborne clearcoats available, however it is mostly basecoat that utilizes water technology. Solvent paint lines utilizes various petroleum based products for paint delivery.

Basic Paint Technology

Automotive paint technology has made significant advancements over the years, more or less you could basically class the products into 2 categorized, Thermoset & Thermoplastics.

Thermosets - These are the products that cure irreversibly. They require a catalyst which causes a chemical reaction creating a cross linked product. This would typcially include your clearcoats,primers,sealers,panelbond,bumper repair materials & even plastic bumpers themselves.

Thermoplastics - These are products that remain soluble after drying. They are usually 1 component (no hardener) and do not cross link. They can be broken down by whatever solvent they are being reduced with. This would include your basecoats, 1 component primers/paints, 1 part repair materials (ie.. window urethane/seam sealers).

What is Crosslinking?

Crosslinking is a chemical reaction that causes a group of polymers (sythetic or naturaly existing materials) to bond together with a linkage. Crosslinking produces one large molecule of your paint film, it makes it very strong and durable. The linkage depends on the resin (ie epoxy, urethane, polyester) & each linkage has its advantages and disadvantages. Here's a look at a few different types of resins:

Epoxy - Epoxy forms the strongest bond because of the unique crosslinking network produced. Epoxy provides superior adhesion and corrosion resistance. The biggests advantage epoxy offers is its strength and durability, drying times are generally slower. Epoxy resins are also broken down easily by UV rays which does not make epoxy coatings ideal for topcoats.

Urethane - Urethanes are produced by the reaction of disocynates and di-alchols. They produce a strong cross linked urethane chain. Urethane has a great deal of flexibility in the types of products it can be created for. It is know for its quick dryinig times. Uses include primers, clearcoats, basecoats, structual adhesives, bumper repair adhesives.

Polyester - Polyester forms a strong bond utilizing the ester linkage and can be further reinforced with fibers to improve it. Polyester has the highest tendancy to shrink but is low in cost compared to the other resins. Uses include bodyfillers,fiberglass, primers & some basecoats.

Factory vs Refinishing Procedures

For the most part the same resins are use just in a different way. Epoxy can be applied through the electro-deposition rather then spraying. Urethane products are usually sprayed and then heat activated. The products are provided with the hardener in it and are designed not to activate until they reach a certain temperature, usually around 200 degrees. There is little difference in the durability between these types of applications. Factory paint is baked only for the purpose of activating the urethane clearcoat and producing more vehicles.

Basic Dent Repair Steps

Preparing for filler

• The first thing you want to do is start with a clean surface, soap/water & wax remover before you begin.
• Bring the metal back to shape as best as you can with the least amount of damage possible to the metal. If you can access the backside of the panel push the dent out and use a hammer and dolly to straighten out the metal. If you cannot access it you can use a uni spotter to weld on pegs to the metal that you can use with a slide hammer to pull out the dent.
• Once you have your metal as straight as possible, remove the paint down to the metal. Use a grinder or coarse sandpaper on a sanding machine.

Applying your filler

• Mix you bodyfiller according to the data sheet of the product your using. Typically you will need to add 2-3% creme hardener to your bodyfill before its ready to be applied. Mix using downward pressure to squeeze out any possible air pockets that can lead to pinholes.
• Using a spreader, apply your filler to the metal you exposed in the preparation. It is better to gradually apply your filler rather then to blob it all on at once.
• Your filler has a period of time around 7-10 minutes after applying where it isn't fully dry but not too wet. On larger dents you can take advantage of this by shaping your filler using either a cheese grater or some 40 grit sandpaper on a block. When using a block the 40 grit will cause your filler just to flake off and not actually gauge the filler with the scratch. If your 40 grit causes sandscratches then you've waited to long and you should not continue doing this.
• Block sand your filler with some 80-120 grit until the edges have leveled out
• If you filler is not straight at this point, reapply and repeat this process.

Apply a Finishing Putty

• These are the same as a regular bodyfiller but are thinner and designed to sand easier. Mix and apply the same way as your bodyfiller.
• You can catch this filler in a semi-dry stage too, but at this point you should only use 80 to quickly smooth out the area.
• Once dry, switch to a 120 and sand until your filler is almost perfect. At that point you can switch to 180 and sand until perfectly straight.
• Inspect your filler for pinholes and other imperfections. If you find anything you should repeat this process or reapply a very tight skim to the affected area.

You can also apply an epoxy primer to the metal at the beginning for maximum corrosion protection. This is a debatable topic, the bodyfiller manufactures don't advise it but the paint manufacturers do.

After this is complete you can begin your preparation steps

Painter Excuses

Painters Excuse's

here's a collection of some excuses many have heard (or used) in the bodyshop.

I thought the molding would cover it

The rep told me to do it that way

It won't look so bad outside

It was painted before

It's just a blend panel

It probably had overspray before it came in

It's as good as the bodywork

The scale needs calibrating

It's too cold in here

It's too hot in here

Their not stonechips, their fisheyes

And the number one excuse:

It looked good.......until I cleared it!

The Value of a Good Cleanup

The Value of a Good Cleanup

It's amazing how many times we have customers pick up their vehicles after a collision repair and the first thing they notice is how shiny & clean the car is. Often they don't even look at the repair!

One of the best things you can do for your business is take an extra bit of time on each vehicle and make sure they leave looking flawless! Who knows, 5 minutes spent polishing out a scratch may lead to a $5000 referral.

Make sure your shop is stocked with products that can make a good cleanup effortless. A quick acid wash on some wheels can make the worst looking wheels look like brand new. A quick run over some headlights can make a huge difference.Here's an example of what less then 5 minutes can do:

Before Polishing	After Polishing

(I know they're different sides, I wasn't thinking right today! but you get the idea)

Interior cleanups will blow some people away. Customers are constantly amazed that we’ve taken the time to wipe down every piece of trim and vacuumed out the entire vehicle, even on a simple bumper job. The impressions this leaves with them generates a ton of referral work, never overlook the value of a good cleanup!

And one last thing, Always clean off overspray!!! Even if you claim it was on it before it came in. It’s your’s now!