collision repair and auto painting

[oliver.r]

bump, i need to stop being lazy

[bmwstephen]

Oliver,

with car companies utilizing high strength glue in place of traditional welding and bolting procedures, do you forsee any issues with this type of process? Unlike a clean weld or proper bolting application, I imagine this type of glue will raise up concerns with reliability in terms of age and environmental conditions?

[oliver.r]

almost every car newer than 2011 has bonded panels to a certain extent.
so brands do door sking (vw) some even do qt panels, i really like bonded panels, it makes repairs a lot faster and cheaper, they also hold up just as well as welded panels (so far)

[bmwstephen]

my next set of questions is regarding the controversial body repair: PDR. I know throughout this thread you have suggested this sort of repair is a slippery slope but I want to dive into the subject as I'm sure you've seen good as well as bad repairs. The information might be useful for those who want to keep as much of the original paint and body in tact as possible.

1) As I understand, PDR requires massaging the dent from underneath with a special tool, is this the only procedure for PDR? If not, what are the others and when does a situation require one or the other(s).

2) you once mention that PDR could cause rust if not done properly but how so?

3) are there areas on the car where PDR is impossible, whether it be from an access standpoint or simply material issue? For example, A/B/C pillars tend to be areas with higher structural integrity and more difficult to access from behind.

4) if the vehicle has its original paint, IE 30 year old enamel paint. Will PDR cause the paint to crack during the "massaging" process that pushes out the dent?

5) will the reformed metal area (post-pdr) be weaker and more susceptible to being redented?

6) Is it truly possible to remove a dent? I can barely pdr a dented soda can back to its original smooth finish.

[oliver.r]

I am by no means a expert or claiming to be a expert when it comes to pdr. I will answer these questions to the best of my ability.

my next set of questions is regarding the controversial body repair: PDR. I know throughout this thread you have suggested this sort of repair is a slippery slope but I want to dive into the subject as I'm sure you've seen good as well as bad repairs. The information might be useful for those who want to keep as much of the original paint and body in tact as possible.

1) As I understand, PDR requires massaging the dent from underneath with a special tool, is this the only procedure for PDR? If not, what are the others and when does a situation require one or the other(s).

i do not know what special tools are used by pdr repair guys or how they really do it
2) you once mention that PDR could cause rust if not done properly but how so?
rust is mainly caused by the whole that is drilled for access of the tool in the jamb of a panel. for example, say you have a dent in your quarter panel. some PDR guys will drill a hole on the b pillar jamb to access the inside of the panel. when drilling the hole the metal shards fall in to the panel rusting in the panel, inside of the panel were the hole was drilled there will be exposed metal were corrosion protection was not re applied.
3) are there areas on the car where PDR is impossible, whether it be from an access standpoint or simply material issue? For example, A/B/C pillars tend to be areas with higher structural integrity and more difficult to access from behind.
any area of the car were there is overlapping metal, pillars, roof edges, some areas of the hood etc.
4) if the vehicle has its original paint, IE 30 year old enamel paint. Will PDR cause the paint to crack during the "massaging" process that pushes out the dent?
im sure it can cause the paint to crack but im not sure

5) will the reformed metal area (post-pdr) be weaker and more susceptible to being redented?
only if its a large dent, if a metal is over worked it gets "work hardened" witch makes it more brittle but PDR would never be able to fix a dent that is that bad
6) Is it truly possible to remove a dent? I can barely pdr a dented soda can back to its original smooth finish
apples and oranges. sheet metal on a vehicle has a different memory than the aluminum on a soda can so yes i think its possible to completely remove a dent

[bmwstephen]

Oliver,

have you heard of zinc powdered paint? Is it any different from etching primer?

I have heard that type of paint being used for post paint body work such as drilling holes to mount spoilers or side skirts

[bmwstephen]

Can urethane paint be used as touch up paint? The over the counter paints I have seen are usually laquer based and i dont think it is as stable

[oliver.r]

Can urethane paint be used as touch up paint? The over the counter paints I have seen are usually laquer based and i dont think it is as stable

I don't think you can buy lacquer any more in CA. if you get regular urethane paint and you use it as touch up with out the catalyst it wont dry so all the dirt from the environment will stick to it and just make a black spot were you applied the touch up. on the other hand, if you apply the catalyst to your paint, your touch up is only going to last a few minutes in the can before it coagulates

[bmwstephen]

I don't think you can buy lacquer any more in CA. if you get regular urethane paint and you use it as touch up with out the catalyst it wont dry so all the dirt from the environment will stick to it and just make a black spot were you applied the touch up. on the other hand, if you apply the catalyst to your paint, your touch up is only going to last a few minutes in the can before it coagulates

The overcounter autozone touch up paint and even the oem bmw touch up paint i recieved indicated laquer on the label.

I know Dr. Colorchip sells enamel based touch up paint and it ships from florida. They seem to be the best solution but im not sure if their enamel paint is as crappy as CA

[oliver.r]

The overcounter autozone touch up paint and even the oem bmw touch up paint i recieved indicated laquer on the label.

I know Dr. Colorchip sells enamel based touch up paint and it ships from florida. They seem to be the best solution but im not sure if their enamel paint is as crappy as CA

well keep in mind, if paint is sold from a retailer in CA it has significantly lower VOC levels than other parts of the country, specially florida. im sure that if you get anything from out of state it will be better quality

[bmwstephen]

well keep in mind, if paint is sold from a retailer in CA it has significantly lower VOC levels than other parts of the country, specially florida. im sure that if you get anything from out of state it will be better quality

Interesting...

So for example an enamel paint packages at a maaco located outside of California will have higher voc/durability?

[oliver.r]

dosnt mean that it will but its legal to have higher VOC

[bmwstephen]

I don't think you can buy lacquer any more in CA. if you get regular urethane paint and you use it as touch up with out the catalyst it wont dry so all the dirt from the environment will stick to it and just make a black spot were you applied the touch up. on the other hand, if you apply the catalyst to your paint, your touch up is only going to last a few minutes in the can before it coagulates

Oliver,

I just want to revisit this one more time before I rule it out completely. If urethane paint does not have a catalyst it'll take longer to dry as I understand. However, if applied in small dabs on like a rock chip, won't they dry relatively quick?

Otherwise, my only choice is to see if a paint shop can mix me some acrylic enamel to touch up on single stage paint (since lacquer will harm SS enamel) because I believe it dries almost as fast as lacquer

[oliver.r]

urethane I s2 part. just buy the catalyst and mix it in small quantities

[bmwstephen]

urethane I s2 part. just buy the catalyst and mix it in small quantities

I think the minimum order for any paint is 1/2 pint so that's a lot. Do you happen to know the shelf life of non catalyzed urethane paint?