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spi epoxy test

35K views 242 replies 28 participants last post by  dinger 
#1 ·
i think this will be about the 5th time this has been done on this board over the years . when the bs gets deep someone does it.
this test panel was sanded with 80 grit and cleaned with solvent base cleaner.
shot 2 med wet coats with a 1.4 at noon yesterday .
80 degrees in my booth
after approx 18 hours of cure
scrubbed with lacquer thinner until rag dried

only some slight residue came off . look close and you'll see my finger prints so i was not being gentle .
now this should put this to rest for a few years again .

this test was done to help those who do not post but need correct info on products or are looking for help. please do not move it to the paint only sub forum . i do not use cheap 3rd line paints so i can offer no help there . that seems to be the main reason for the sub forum.

signed " one of the spi thugs "
 

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#2 ·
Thank you very much, what part number is the epoxy? I have never gotten any but plan on it and I see the three different colors and what not, so I want to be sure what I am getting.

Brian
 
#4 ·
Apparently I missed the whole thread...and now I see a "paint" sub forum...(don't know why there needs to be a paint sub forum...but anyway).

Did I miss something that maybe I should know about? I've read between the lines and apparently a thread got tossed and all I've heard is that it may have something to do with...or the thread was SPI "cult" suggestive.

If somebody can fill me in...even a PM would be appreciated if this is that delicate a topic. The reason I ask is that I've become a fan of SPI products and any information regarding this product...I'm interested in.

Ray
 
#5 ·
look in the dump . one of the stupidest threads i have seen here in the 10 years i've been here.

the sub forum ranks right up there with it . useless and just confuses people. i hate to inform them but it is body and paint. always has been .
 
#7 ·
Don't know how to check the dump but will try to figure it out. I agree with the paint and body staying paint and body...why, that's what it is, paint and body...it's not metal work, filler work, primer work, prep work and paint work. They are so dependent on each other they need to be in the same category or, as you mentioned, it'll just confuse everybody.

Ray
 
#12 ·
I use SPI epoxy exclusively, so don't get me wrong, but
I don't think weather lacquer thinner can disolve the surface
proves anything.
Wouldn't it hold the paint better if the top coat DID dissolve
into it a little?
If it's so hard that there can be no chemical bond, then only
the scratches hold the paint on? Is that better?
I just don't understand what all the fuss is over, it's
a moot point to me. I know it's good primer, I don't care
if it wipes off or not, it's covered with paint.:thumbup:
 
#25 ·
I use SPI epoxy exclusively, so don't get me wrong, but
I don't think weather lacquer thinner can disolve the surface
proves anything.
Wouldn't it hold the paint better if the top coat DID dissolve
into it a little?
If it's so hard that there can be no chemical bond, then only
the scratches hold the paint on? Is that better?
I just don't understand what all the fuss is over, it's
a moot point to me. I know it's good primer, I don't care
if it wipes off or not, it's covered with paint.:thumbup:
I'm surprised at you Jim, I'm sure you know that all epoxy manufacturers recommend sanding and recoat with epoxy before anything else if out of the recoat window. Then you can get a chemical bond.
 
#13 ·
I'm sure it would absorb a base when applied wet on wet. more or less just showing you how strong the barrier is against water vapers/lock out. Impressive. I really wish Shine would have sprayed another brand or two at the same time to show comparisons. I'll be ordering a gallon for my Stang for final block when my lazy butt gets around to it.
 
#14 ·
I don't see much reason for the paint sub forum myself. As to the poster that originated the SPI thug term, he was called out, and didn't bother to substantiate his claims. As far as Barrys' products go, I don't recall one complaint about his stuff. Can't say that about most products. Barry has been an asset to this forum and he does have his fans. I don't know of any other owners of paint companies that you can call on the phone for help.

As far as the sub forum goes, if it turns out to be just a bunch of opinions about paint, it really has no technical merit and will probably die a slow quiet death.
 
#16 ·
If there is such a thing as an "SPI Thug", is there a form you need to fill out to become one, or is letting people know that there is an alternative to the higher priced, high end primers and clears from the major manufacturer's enough to inducted into this group. If not, where do I sign up?

As many of you people know, I've spent a lot of time working for and have been a Rep for several of the major aftermarket paint manufacturer's. Do I like the products that they put out? Absolutely, they all work, some product lines better than others but, they all work. If they where designed to fail, chances are the companies wouldn't be around.

When I was a Rep for ICI (now Nexa) in the 80's and 90's, I was doing what I loved as a hobby, Restorations and Customs. I used PPG's DP 40 Epoxy Primer (Notice the part number...DP 40...no LF after the 40. That was back in the day that DP 40 contained lead and now the DP 40 LF product, the LF stands for Lead Free) no matter what primer or top coat came after...DP 40 worked that well. Even after they took the lead out, I still used it...and did so until I was informed about SPI. I tried the product myself on test panels, I abused the product on test panels. This was 6 months ago or more and the SPI Epoxy has out performed what I had been using, let alone the fact that I can easily sand SPI and sanding DP 40 LF is virtually like rubbing 2 rocks together. So I guess my question to the person that coined the phrase "SPI Thug", is...If I find a product that I like better than what I've been using, is telling other people about it wrong?

I have my preferences with other products as well, I like 3M's Perfect-it polishing compounds and equipment over other supplier's products...I like 3M's Panel Bond Adhesive and use it exclusively...I also mention my preference to anyone that asks. I guess this makes me a "3M Thug" as well.

Ray
 
#15 ·
You do now. Here at Master coat, we answer the phones from 8 AM to 10 PM. I may no longer be the owner, but when the phone rings and they're not quick to pick it up, there will be hell to pay.The phone rang Christmas morning ,turned out to be a lady looking for free telephone. This is the only post I will make in regard to this topic. If you have a technical question I'll be most happy to answer it to the best of my ability
 
#17 ·
there are those who do it right and those who stayed at motel 6 once.
this happens anytime 2nd line or relabeled crap is brought up. some guy comes on praising eastwoods new paint or summits new paint or how they painted their show car with omni . the smart thing for a professional to do is ignore and not post. but like barry told me once , if we dont speak up some poor guy with 2 years into his hotrod tries something and then discovers it all has to come off . when on a tight budget this is a disaster . but the google expert is nowhere to be found when it happens.
when i am building an engine i go to a professional for advice. i do not want to hear a bunch of bs from someone who changed an intake . take a look in the engine builders forum . those poor guys have been run ragged by google experts reading hotrod magazine.
maybe a better sub forum would be one for professionals to answer question but only after proof they do it for a living or own a shop. but that wont happen .

spi thug and proud of it ................... use to be a ppg thug but nobody whined about it.
 
#19 ·
there are those who do it right and those who stayed at motel 6 once.
this happens anytime 2nd line or relabeled crap is brought up. some guy comes on praising eastwoods new paint or summits new paint or how they painted their show car with omni . the smart thing for a professional to do is ignore and not post. but like barry told me once , if we dont speak up some poor guy with 2 years into his hotrod tries something and then discovers it all has to come off . when on a tight budget this is a disaster . but the google expert is nowhere to be found when it happens.
when i am building an engine i go to a professional for advice. i do not want to hear a bunch of bs from someone who changed an intake . take a look in the engine builders forum . those poor guys have been run ragged by google experts reading hotrod magazine.
maybe a better sub forum would be one for professionals to answer question but only after proof they do it for a living or own a shop. but that wont happen .

spi thug and proud of it ................... use to be a ppg thug but nobody whined about it.
I have to say Shine, "owning a shop" or doing it for a living is no guarantee what so ever that the guy has the proper information. I will forever be amazed at what some "Pros" will not know. If the information is correct, it's correct, if it's not, it's not. This is why these forums are so great, they are open to everyone. It is the best place ever to get a balanced idea on issues. This discussion proves it, we have gotten a very good idea on it what is right and what is wrong. Simply presenting the case as you have here, says it all, done deal. It doesn't matter what anyone says, that is a done deal. Thank you! :thumbup:

Brian
 
#21 ·
shop owner ..... yeah brian i have to agree there . many are dumb as a tree stump on paint. worked for a few over the years. but the bottom line is guys come here for help . just like i do on engines . far too often things are lead astray by posers and wannab's .

and dont bring up anything 80's please :( the whole industry went stupid for a time. i still have a lot of my old training books. i look back sometimes and geeze we were fed a line of bs. kronar was junk in anyone's book .
look at k36 . you want to talk about a cult following . even ppg does not understand why it still sells .
 
#27 ·
Well Brian and Chevymon, your both right, sanding generally gives you a mechanical bond, however, by opening up the Epoxy primer, your allowing for an easier chemical bond as well. In order to get a chemical bond, the solvents in the product being applied go through the substrate down to metal, bounce back up and then dissipate into the atmosphere. While the solvents are moving down through the sanded substrate, they are reacting with the substrate and bonding. If the substrate is not sanded, the solvents from the freshly sprayed product can't break through the original substrate and will peel off when dry. So it's not just the footprint of the sand scratch that helps with adhesion, it's the fact that it has opened up the substrate and allowed the chemical adhesion reaction to occur.

Here is an example. Clear coat can be sanded with 1,000 grit or even 1,500 sand paper and when you top coat it, the new product sticks...a very small sand scratch footprint, but adhesion is still there.

Hope this explains a bit further.

Ray
 
#28 ·
Well I'm confused, I thought it was only mechanical when you had to sand it.
That's why you sand it, no chemical bond so you need a mechanical which
means scratches for it to hold on to. Chemical means not needing sanding, yes?
Anyway-if solvents can go through the epoxy primer then
I can't believe it's waterproof like it's advertised, right?
Can it be a sealer and waterproof but solvents can penetrate to the metal?:confused:
 
#31 ·
Well I'm confused, I thought it was only mechanical when you had to sand it.
1) That's why you sand it, no chemical bond so you need a mechanical which
means scratches for it to hold on to.

2)Chemical means not needing sanding, yes?

3)Anyway-if solvents can go through the epoxy primer then
I can't believe it's waterproof like it's advertised, right?

4)Can it be a sealer and waterproof but solvents can penetrate to the metal?:confused:
What I've done is broken down your questions so that I can be sure that I am answering your questions to the best of my ability.

1) Chemical adhesion is a totally different animal than mechanical...mechanical does mean "sticking to sand scratches"...you still have chemical adhesion regardless, if you sand something and open up the pours, you will have more chemical adhesion as well as mechanical.

2) Chemical adhesion does not mean that you don't need to sand a substrate. With respect to Epoxy primer you have chemical adhesion qualities for a period of time without sanding because the pores in the primer stay open for a certain amount of time. After that window, you need to open those pores again by sanding so that you get chemical adhesion as well as mechanical.

3) As I mentioned in my previous post, water molecules are larger than solvent molecules so something can be waterproof and not be solvent proof. Solvents used in paint have harsher more active ingredients in them than water which means they can penetrate or breakdown a cured substrate easier than water, not just because of the size of the water molecule versus the solvent molecule, the sheer chemical make up of a solvent versus water makes solvent penetrate easier.

4) Simple answer to question #4 is yes. Epoxy primer can be a waterproof sealer but solvents can penetrate the sealer and go down to the metal, especially if the Epoxy has been sanded and opened up so the solvents have easy access.

I know it's confusing but...and...I hope this explains things a bit more.

Ray
 
#29 ·
It is confusing, the water molecule is larger than the solvent molecule, so, a product can be waterproof but that doesn't mean that it's not penetrable by other media. Another example, (this might be a bad example but it may get the point across) the filter in your paint booth stop air born dirt and dust but still allows air to pass through them, why, because the dust and dirt is larger than the air molecule.

In the ideal adhesion world, you have both mechanical and chemical adhesion. The chemical adhesion is the chemical joining between two products. When you sand a primer, your opening up the pours so that whatever you put on top will sink into the primer and bond with the chemicals in the primer.

Lets try it this way. We've all heard about solvents being to harsh. When a solvent is to harsh and it's applied to substrate it can cause the substrate to wrinkle....why...because it penetrated the substrate so aggressively that it broke up the molecular integrity of the substrate (think of the true meaning of the word solvent...it means to penetrate and break up...like solvents for cleaning grease off of parts like bearings). The ideal solvent for paint will not break up the substrates molecular integrity, it will soften it enough to allow the new top coat to penetrate and bond with the existing substrate.

I hope this explains it a bit better.

Ray
 
#34 ·
It is confusing, the water molecule is larger than the solvent molecule
No, Ray, I play a scientist for 45 hrs a week and I'm here to tell you a water molecule is most certainly NOT larger than a solvent molecule. I don't even where you would have heard this!

Let's compare water and a solvent:

Water: H20; F.W.=18; molecule diameter=1.93A

That's two Hydrogens and one oxygen


Pick a solvent. For instance, acetone

Acetone: C3H6O; F.W.=58; molecular diameter=3.08A

That's 3 Carbons 6 Hydrogens, and 1 Oxygen.

In fact, almost any molecule you can pick of anything is going to be larger than a water molecule.
 
#41 ·
Then I stand corrected and I thank you for pointing that out. I wouldn't argue with a scientist. This however is what I was told (at an ICI seminar if I'm correct) and not having your background, I believed it.

Would it be correct then in saying that a solvent such as a reducer (I realize that water is a solvent as well) would have active ingredients in it that would start to dissolve or break down or should i say open up a substrate faster than water...that's why something can be waterproof (to a point) and not solvent proof?
It hurts my head to even think where to begin...the general principle is correct, but at the same time it's not accurate. It's correct because you make accurate use of the term 'dissolve,' as that's what's happening. Acetone, for example, is the solvent, the solute would be the components of the paint, etc. Thus this is dissolved by the acetone and it all becomes a single solution.

Where it's not accurate is looking at it as if it breaks down something 'faster.' There are 4 chemical conditions that define a solvent's abilities: hydrogen bonding, polarity, dipole moment, and polarizability. Don't worry, I had to consult my chemistry text to make sure I got those right, and is bringing back lovely memories of my undergrad. But I only state that to demonstrate the complexity of everything at play.

To break it down further, solvents are classified into 2 categories, polar and non-polar. There's a textbook phrase in chemistry that goes 'like dissolves like.' Meaning, polar solvents can only dissolve polar compounds, and nonpolar solvents can only dissolve nonpolar compounds. Water is polar, oils and waxes are non-polar, this is why these two will separate. But sugar is polar, and you can dissolve that with water.

But now let's make this even more confusing, water and acetone are both polar. So WTF! you say. Well that's because there are two 'sub-genres,' if you will, of polar solvents--protic (water), which solvate negatively charged ions (anions), and aprotic (acetone), which solvate positively charged ions (cations). Thus the mechanism by which these two solvate are largely divergent. So the chemical makeup of paints or primers would have to be largely cationic. Proteins, which are what I work with, tend to be negatively charged (anionic) and tend to solubilize in water pretty well, though they may not be stable long term.

So what does all that mean in simple terms? Well, there's a giant chemical orgy and in the simplest terms, ions are getting exchanged all over the place, which literally rearranges compounds. But certain things are only capable of dissolving certain things, all due to very specific chemical properties of the solvent--which are the four solvent properties I listed earlier.

You being a scientist and acetone being a fairly aggressive solvent...is it the 3 carbon atoms that make acetone that aggressive? Or is it the combination of the carbon and hydrogen together with the 1 oxygen atom that make it a liquid that causes it to be aggressive.
It would be due to the fact that the specific elemental arrangement of these carbons, hydrogen, and oxygen, and their specific ionic properties define the four characteristics I note above. So I had to look it up, but acetone has a pretty large dipole moment, which is important in the chemical reaction that takes place. Let's just leave it at that :thumbup:

I'm a veterinary microbiologist, not a chemist (though chemistry is central to all science), so don't get too eager in your questions because I DON'T know it all!!! ;)
 
#45 ·
It hurts my head to even think where to begin...the general principle is correct, but at the same time it's not accurate. It's correct because you make accurate use of the term 'dissolve,' as that's what's happening. Acetone, for example, is the solvent, the solute would be the components of the paint, etc. Thus this is dissolved by the acetone and it all becomes a single solution.

Where it's not accurate is looking at it as if it breaks down something 'faster.' There are 4 chemical conditions that define a solvent's abilities: hydrogen bonding, polarity, dipole moment, and polarizability. Don't worry, I had to consult my chemistry text to make sure I got those right, and is bringing back lovely memories of my undergrad. But I only state that to demonstrate the complexity of everything at play.

To break it down further, solvents are classified into 2 categories, polar and non-polar. There's a textbook phrase in chemistry that goes 'like dissolves like.' Meaning, polar solvents can only dissolve polar compounds, and nonpolar solvents can only dissolve nonpolar compounds. Water is polar, oils and waxes are non-polar, this is why these two will separate. But sugar is polar, and you can dissolve that with water.

But now let's make this even more confusing, water and acetone are both polar. So WTF! you say. Well that's because there are two 'sub-genres,' if you will, of polar solvents--protic (water), which solvate negatively charged ions (anions), and aprotic (acetone), which solvate positively charged ions (cations). Thus the mechanism by which these two solvate are largely divergent. So the chemical makeup of paints or primers would have to be largely cationic. Proteins, which are what I work with, tend to be negatively charged (anionic) and tend to solubilize in water pretty well, though they may not be stable long term.

So what does all that mean in simple terms? Well, there's a giant chemical orgy and in the simplest terms, ions are getting exchanged all over the place, which literally rearranges compounds. But certain things are only capable of dissolving certain things, all due to very specific chemical properties of the solvent--which are the four solvent properties I listed earlier.



It would be due to the fact that the specific elemental arrangement of these carbons, hydrogen, and oxygen, and their specific ionic properties define the four characteristics I note above. So I had to look it up, but acetone has a pretty large dipole moment, which is important in the chemical reaction that takes place. Let's just leave it at that :thumbup:

I'm a veterinary microbiologist, not a chemist (though chemistry is central to all science), so don't get too eager in your questions because I DON'T know it all!!! ;)
Although I didn't fully grasp everything that you posted, I did understand a fair amount and what I understood was that because water (being a solvent) has different properties, the chain reaction of water on primer is different than say the chain reaction of reducer on primer, making primer more water proof than reducer.

I will stay with my original statement though that sanding a primer aids in mechanical and chemical adhesion of primer to top coat.

I know this is going to sound anal...and I know it is....but, I dug up my old notes from the 80's...and in 1986 this was passed out by a CIL trainer in Edmonton, not ICI, which documented that "because the water molecule is larger than the molecules found in CIL's 2K primer, the water molecule can not penetrate today's high build catalyzed primers". Now I wish that I would have read that statement over before I posted...I would have questioned the fact that water can't penetrate high build primers because as we now know, they can.

So, again I thank you for clarifying the water molecule thing, the last thing I want to do is pass on information that isn't correct.

Ray
 
#33 ·
Your not wrong, you will have chemical bonding using epoxy primer or whatever...you will have chemical bonding if you sand or open up epoxy primer and top coat it with base coat, single stage, more epoxy primer...if the epoxy has gone passed the window and you sand it...sanding it opens the window for you...because the the primer is sanded you will have mechanical adhesion...because the primer is sanded and opened up, you will have chemical adhesion.



I'm hoping this helps

ray
 
#44 ·
This is my first experience with any kind of forum, and God I never knew what I was missing. I've turned into a teenage girl, first thing in the morning I turn on my computer just to watch this forum and all the excitement. I've been in the paint business for 23 years I never knew paint could be so exciting.LOL Mr. gearhead I must say I like your style and you bring up a lot of valid points.
 
#53 ·
Consider this.
My good friend and "fishing buddy" owns a "Stories" autobody
supply shop right here in my area.
If I am going to buy something, I try to buy from him.
I will always try to support my local guy first anyway.
So for me to buy SPI clear and epoxy means I have to be quite
convinced I'm getting something way more than what my friend carries.
And my friends epoxy is actually cheaper to buy.
I am not a SPI brand loyal painter.
I just use what I like the best, no matter who makes it.:pimp:
 
#55 ·
never fails . mine's just a driver so it can look like crap and i'll redo it later.
i will never understand this . just what is the difference ????? i may fudge just a little on bodywork on my shop truck but the finish will be the same as any other car i do.
for the motel 6 guy . i have streetrods out there with 100k miles on them. i have customers with cars i painted in the early 90's and still going. spi wont stand up to daily driving . more bs. edward drives the 37 below almost daily. he delivers meals on wheels in it , goes out to eat or whatever. the blue sedan has over 100k miles on it , the black coupe was painted in 95 .

tell me this. before i switched to spi i used ppg. why no pissing and whining about all the ppg thugs ???? i can tell you why. when someone brings up some converted enamel internet junk those who know try to steer the person in the right direction . low and behold someone who used this crap gets all butt hurt and goes to whining. never mind that several tradesman with 30+ years of fighting this all agree . you see , if our job blows up we have to fix it. if your goes to crap you'll just blame someone or something else and drive it. not an option on a 150k car .

in case you didn't know all the majors make their money in collision work . not restoration . so just how much r&d money do you think they spend on longevity ? the car is repaired and likely sold after 6 months never to be seen again. rock hard , chips, like buffing concrete but done and gone in several days .

i can assure you if spi fails on me i will be on barry like ugly on an ape. but unlike those others he will actually try to figure out what happened. ppg , dupont ???? they have the same generic answer . the painter screwed up . 9 out of 10 times it is usually our fault but if you think the majors do not ship bad products you have very little experience at this. and they will not stand behind it unless you buy a large amount monthly. the diy guy is screwed .
 

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