What did you do with your truck today, Part 3

[MARTINSR]

Only use it if you REALLY need it. It's harder to sand, it's thicker, only use it if you need it.


Brian

[DransportGarage]

Originally Posted by NorCalGal

I’m thinking about using a polyester primer this time around. Any pro cons or advice on usage.

Both urethane and polyester (and epoxy) have their place. Back in the day I used "Featherfill" (polyester), made by Fiberglass Evercoat, before urethane primers became popular. Once the 2K urethane primers came on the scene at a reasonable price I never went back to the spray polyester, mostly because polyester dried too fast for my liking, and I was worried about adhesion. (...and that was probably because I didn't have a gun setup that would spray it wet enough, and I was too inexperienced to solve the root problem..) Today, if I need to build a thicker film in a given area I'll spread on a skim coat of polyester glazing compound, or even a quality general body filler, which is also polyester. That said, anywhere you need SLIGHTLY more build you could spray polyester rather than slather it on.

I use Southern Polyurethanes' Universal Clear, and sometimes use their forum for technical advice. Many of the contributors on there are working at the professional level and their advice tends to be well above a lot of forums. Here is a link where they discuss your question:

http://www.spiuserforum.com/index.ph...r-primer.5616/

Sherwin Williams gives kind of a "chemists' " perspective here:

https://www.sherwin-automotive.com/m...ethane-primers

If you want hours of fine reading, Google "polyester vs. urethane primer".

[MARTINSR]

Here is a "Basics of Basics" on Paint technology. I wrote this 20 years ago before I had used SPI epoxy primer so it says "hard to sand" and "doesn't fill well" which is WRONG being SPI epoxy primer sands very well and fills very well.


"Basics of Basics" Paint technologies
By Brian Martin

There are many different types (or more correctly, technologies) of products you can use in the restoration or repair of your vehicle. Some have a variety of uses while others are very limited with only a few of specific uses. Proper choice of products can help you get the job done faster and/or help with the longevity of the repair.

Let’s start with some basic definitions. I couldn’t possibly know every paint manufactures terminology or product use. These are generalities and should be used as a guide only to then read the tech sheets of the products you have chosen for proper use. These tech sheets can be found at the jobber and are given away free. Or most manufactures have them on line, USE THEM. They are a wealth of information and can save you many headaches. You don’t need to read every word in the mind numbing text, they usually have a “product at a glance” or something like that will cut to the chase and give you what you need.

Basic terminology’s;

“Solvent” is a generic term and refers to any “reducer”, “thinner” that is used to reduce the viscosity (“thickness”) of a product to aid in spraying or applying. It could be acetone, lacquer thinner, urethane reducer, a special “basecoat” reducer, water, alcohol, etc. These solvents ARE NOT INTERCHANGEABLE; each product MUST be used with the specific solvent recommended by the manufacture.

“Etch primer” an acid containing primer.

“Primer” a product that can be applied to bare metal

“Surfacer” (or “primer surfacer”) A primer that has “body” or solids and is used to fill imperfections and provide a film thickness to sand or block a surface to a smooth base for paint.

“Sealer” a non-sanding product that is applied prior to painting.

“Primer-sealer” A sealer that can be applied over bare metal and then top coated without sanding.

“Flash time” the time you allow the solvents to evaporate out of the film you have applied.

Basic technologies;

“Single component” or RTS (Ready To Spray). This is a product that uses no additional components. Just pour it from the can into your gun and shoot. Examples are: Some plastic adhesion promoters and primers and even some top coats like vinyl colors.

“1K” This is a product that uses no hardener, catalyst, activator, etc. It may have an added solvent, but no hardener or activating reducer. 1K products like RTS dry with the evaporation of solvents and are soluble, meaning that they are could be wiped off with a rag soaked with lacquer thinner. They could in THEORY be scraped off and put in a can with solvent and stirred back to a sprayable condition. Of course ALL RTS products are 1K. Examples: All lacquer products, some synthetic enamel products, and some acrylic enamel products. Because of the low VOC regulations the 1K product options are getting scarce, with most limited to “specialty products” like adhesion promoters.

“2K” or “Two component” is any product that uses a hardener, activator, catalyst, etc. It may or may not use a third component in the form of a solvent. 2K products don’t “dry” like a 1K. The 2K product “cures” by molecules linking together to form a whole new compound. Most high quality 2Ks are insoluble after a full cure and will not soften when exposed to solvents like thinners or gas. Examples are urethane under coats and top coats. Epoxies, ISO free products that use a hardener, etc.

Basic tip, ALL 2K products should be mixed as accurately as possible. As a rule 2K products need a minimum of 55 degrees to cure with an ideal minimum of 65 degrees. MIX THEM AS DESCRIBED BY THE MANUFACTURE. They have spent hundreds of thousands, possibly millions of dollars developing the product, they WANT it to work as BEST it can. Do as they say, don’t become a “Junior Chemist”.

Types of products and their uses;

Etch primers (some are 2K)

“Wash” or “Vinyl wash” are for bare metal applications for the ultimate in adhesion and corrosion protection. They are very low in solids with next to zero filling qualities. Some are even semi transparent. They are usually not to be top coated with paint. You apply them to aid in adhesion and corrosion protection under other undercoats such as epoxy or urethane primers.

Benefits:

- Very thin, keeps down film build

- Cost effective

- Fast application

- Non-sanding

- Super high corrosion protection.

Disadvantages:

- Some have a very small re-coat window

“Etch primer” (some are 2K)

Typical “etch primers” have much more solids and body than “wash” primers. They are more forgiving than “wash” primers, one thing being a much longer re-coat window. They are basically used to aid in adhesion and corrosion protection as with “wash” primer. You would choose “typical” etch over “wash” if you have some paint or plastic filler as a substrate along with the bare metal. Some brands have a recommendation to apply top coats over it also. This could be very useful in a money saving or time saving is important.

Benefits:

- Easy to apply, smooth, easy to sand

- Some can be applied over plastic filler (not that you need it over the plastic filler, but if you have some, it is nice to not have to go around it)

- Some can be top coated, which can be a big time and money saver.

- VERY cost effective

Disadvantages:

- Added product to buy and apply.

IMPORTANT basic! If you have used ANY metal treatment or “conditioner” read tech sheets carefully for compatibility . The acid in the metal “treatment” or “conditioner” can attack the acid in etch primers and it can LOOSE adhesion from the metal!

Urethane primer (2K) Urethane primer is the most common primer used in auto body and restoration by far. It has good solids and fills well. It is easy to sand and can provide you with a perfect body when blocked properly. Care should be taken when applying it as to not use too much. It can shrink when applied too heavy. It is the best all around primer for applying over plastic body filler and for surfacing your work. If used properly it provides the proper film thickness under top coats and is the perfect substrate for bs/ss and SS.

Benefits:

- Easy to apply, and sand.

- Applies smooth.

- Fills well with minimum of shrinkage

Disadvantages:

- Contains Isocyanates.

- Should always use an etch primer under it.

Epoxy primer (2K)

Epoxy is a good corrosion fighter. It is has a very sticky resin and will provide good adhesion to MOST substrates. It typically has poor filling and sanding qualities (that sticky resin makes sanding difficult) . It is ideal for use as a “primer/sealer” on bare metal that requires no surfacing.

Perfect for frames and components, radiator supports, items that are sandblasted and you only need to prime and paint. You use it as a non-sanding “primer/sealer” and then paint right over it.

Benefits:

- Good chip resistance (it isn’t as hard as a urethane)

- Perfect for a “primer/sealer” over bare metal.

- Etch primers can skipped because of its excellent adhesion and corrosion properties. (although for maximum corrosion protection apply a wash etch under the epoxy)

- Provides good base under plastic body fillers (skip the etch if you plan on using plastic filler over epoxy)

- Epoxy has no isocyanates .

Disadvantages:

- Poor sanding qualities

- Poor filling

Polyester primer (2K)

Polyester is a very specialized primer used in very small amount in most shops across the country. But when it is needed, it does a job like no other. Polyester has a huge solids content and will fill 80 grit scratches in one coat or 36 grit in two or three! Urethane for instance provides about ½ or ¾ mils per coat while polyester can give you as much as 4 to 6! Because of it’s high solids, it shrinks very little. It is basically like spraying polyester putty. Look for a manufacture that has a recommendation to apply etch primer under it. I see NO reason to use polyester on a straight panel. It is for use only when you need some serious filling and surfacing.

Benefits:

- VERY high filling

- Low cost

Disadvantages:

- Very high texture

- Harder to sand than a urethane

- Possible need to purchase a large gun to shoot it.

“ISO FREE” (2K)

“ISO FREE” is a urethane type primer but without the harmful isocyanates that a urethane contains.

The problem is ALL refinish products should be used with the same care and concern for your health and others. ISO FREE is like “low tar” cigarettes, don’t kid your self, it is still VARY harmful.

Benefits:

- Isocyanate free

- Smooth, easy sanding

- Good filling

Disadvantages:

- You need an etch over bare metal before it.

Basic tips… Etch primers can be skipped on spots of bare metal smaller than a dime or so when using all primers listed.

Most “quality” 2K primers need NO sealer before top coating with bc/cc or SS when applied properly.

Sealers

All RTS or 1K sealers should be reserved to VERY low end jobs to save money. They do NOT offer the benefits of a 2k, PERIOD.

Reasons to use a sealer:

- Makes up for “some” poor preparation

- Provides a uniform color for better coverage when you apply paint.

- Helps with providing a uniform substrate for paint.

- Helps provide a better substrate when painting over a 1K primer.

- Can Help with “covering” poor prior repairs

Under collision repair conditions a shop may use sealers on every job as an “insurance” protection against problems. In a restoration environment where complete panels are primed with a 2K there really is no need to use them.

If you have chosen to use a sealer there now are a few more choices to make. First, you need to decide what kind of sealer to use. As I mentioned in the beginning, RTS or 1k could be used to save money. Why put a 1K sealer over your 2K primer (I hope you are using a 2K primer) then apply a 2K top coat? It is like the old saying, “It’s only as strong as it’s weakest link”. If you use a 1K sealer in this fashion it is like replacing a link in your tow chain with a nylon tie!

With 2K there are a few options, epoxy and urethane being the most popular. I don’t feel that there is a huge difference in the two as far as how they apply or work. Epoxy is more forgiving with sensitive substrates. It really comes down to what you feel more comfortable with. The epoxy has no isos so that would be one reason to choose it.

Now that you have decided what sealer to use you have to decide on what application.

Most sealers give you the option of a “wet on wet” (or very close to it) or a full “barrier coat” application.

The difference being with “wet on wet” the sealer is applied and then allowed a short flash time before the basecoat or SS is applied. A “barrier coat” is where the sealer is applied, then allowed to cure or at the very least to totally flash. This allows the sealer to become a barrier so the solvents from the color coat can’t penetrate it and attack the substrate.

The barrier coat procedure allows for he sealer to do MUCH more of what you choose to use a sealer for in the first place. The choice is made taking into account a few factors. How sensitive is the substrate? Or, how aggressive are the solvents in the color coat that you are applying? If it is very hot weather and you are using a slow solvent in the color coat to help it lay out, you may choose to use a sealer because you know that the substrate is sensitive and the slow solvent will attack it.

[NorCalGal]

Thanks a Bob and Brian, Lots of good information there I think I will stick to the SPI 2k surfacer I have.

[MARTINSR]

Polyester is REALLY nice for heavy detailed stuff like on my doors on the inside that have welds all over and around the windows, finishing off bondo in these areas is a pain if you go down to finer paper for regular primer. But with the polyester primer I was able to leave it in 80 grit so I could shape the stuff but not worry about the detail and sand scratches. The polyester primer filled that well and now it's just sanding it with 120-180 and put a few coats of regular fill primer, and sand and paint.

The polyester is especially good on something like a tailgate or a firewall, somewhere that has a lots of lines. You can CUT it flat shaping stuff with coarser paper and then poly prime it like putting a skim coat of bondo on.

Brian

[MARTINSR]

It seems I have a connection with magical musical moments. Just minutes ago I put the wheels on the back of my truck and lowered it off the jack onto the ground for the first time in about 20 years. As I was putting the wheels on the radio was playing some rock and roll from the eighties and I thought that's appropriate, then right as I was finishing tightening the lug nuts "Magic Carpet Ride" by Steppenwolf came on! This my friends was MY music, I have the LP and listened to his music while working on my truck 45 years ago! As I set it on the ground CCR was blasting away, OMG this is so cool!

Brian

[nvrdone]

I can relate. only my music is all on my phone - about 2500 songs all from the 60's to the 80's . plugs into the garage stereo or into the truck for road trips. my favorite is "Hot Rod Lincoln" by Commander and the Lost Planet Airmen.

[MARTINSR]

I feel like a stripper came into my garage and did a lap dance for me! It isn't a big model kit in a million pieces anymore, it's a "truck" that rolled out of the garage onto the driveway for a picture! I can't believe it, holy crap!


Brian

[MARTINSR]

On the song thing, while putting the front together I found that I had screwed up and I had two left had lower front shock mounts and not left and right, CRAP! When I found this out, CCR was on the radio and "Bad Moon Rising" was the song! LOL

Brian

[NorCalGal]

That’s a big step forward..looks good

[DransportGarage]

Originally Posted by MARTINSR

On the song thing, while putting the front together I found that I had screwed up and I had two left had lower front shock mounts and not left and right, CRAP! When I found this out, CCR was on the radio and "Bad Moon Rising" was the song! LOL

Brian

Tell Alexa to play "oldies" and you'll have the truck done by the end of the month...maybe sooner if she plays "One Piece at a Time"!

[oldman3]

Brian, looking good, happy for you...Jim

[MARTINSR]

Originally Posted by oldman3

Brian, looking good, happy for you...Jim

Thanks Jim, I was so beat last night, don't know why I didn't think it was "hard" work, but damn was I beat. My youngest daughters 18th birthday party was last night and I had to take a few family members out there to show them my "truck."

Brian

[MARTINSR]

Thought this was going to be a throw it together afternoon relaxing with a love song on playing in the garage. I was WRONG. This one fender took me 2 friggin hours, I forgot how goofy these were, wow.

I re-shaped the fender a little where the bracket mounts. You know how there is a flat spot right there in the round shaped opening? Well I rounded the metal there to make it look better never thinking that this would change where the bracket bolts. Or if I did think about it I figured it would bend into shape not a problem. Well, that friggin bracket is damn near spring steel! HOLY CRAP was it hard to bend that sucker! Well, I got it bolted in and I then find that the cowl patch panel I made is a bit off, the gap between the fender and cowl side is a bit more than I would like so that will be another thing to work with after I finish the hood. Sorry for the crappy photo of the bracket, it goes from the rad support over to the side of the fender at the wheel opening to support it.

The NSRA mug you will notice is from 1980. I will have a drink in it (beer, water, what ever) as I am working on the truck just as a memory sparker. I entered this truck in that event before it was ready and didn't get it done even though I was working until 2 am for weeks to do it. LOL Geeez, now I can't make it until 2 PM!

Sitting here with a lunch and watching a ball game and hopefully I can get out there and get the other fender on.

Brian

[MiraclePieCo]

Originally Posted by MARTINSR

I re-shaped the fender a little where the bracket mounts. You know how there is a flat spot right there in the round shaped opening? Well I rounded the metal there to make it look better never thinking that this would change where the bracket bolts. Or if I did think about it I figured it would bend into shape not a problem. Well, that friggin bracket is damn near spring steel! HOLY CRAP was it hard to bend that sucker!
Brian

What I usually do with those is just cut them until they fit without tension, then weld the cuts back up.

Must be thrilling to have your truck starting to look like a truck!

[MiraclePieCo]

Removed my drivers door to paint it and the jamb, and install my door seal. This is where I pay the price for having thrown the truck together to get it on the road without doing all those little details!

[MARTINSR]

Got the fenders on WHOOO HOOOO! The second one came way easier than the first thank goodness.

I had forgotten that I left the holes in the fender where the support rod bracket was moved back with the rod shortened to clear the tunnel ram intake on the 235 it had when I got it in '73.

Brian

[MARTINSR]

Originally Posted by MiraclePieCo

What I usually do with those is just cut them until they fit without tension, then weld the cuts back up.

Must be thrilling to have your truck starting to look like a truck!

It IS a truck again, it's a truck not a pile of parts scattered around the yard!

Brian

[oldman3]

Looking good Brian...Jim

[MARTINSR]

Originally Posted by oldman3

Looking good Brian...Jim

Originally Posted by NorCalGal

That’s a big step forward..looks good

Thanks guys!

Brian

[Black_Sheep]

The truck is looking good Brian!

The rain stayed away so I took the '58 to the Buick Club car show on Sunday

[DransportGarage]

Originally Posted by Black_Sheep

The truck is looking good Brian!

The rain stayed away so I took the '58 to the Buick Club car show on Sunday

So, did they appreciate your truck at the Buick Club show?

[Black_Sheep]

Originally Posted by DransportGarage

So, did they appreciate your truck at the Buick Club show?

Some folks did, but stock looking cars ruled the day.

[MARTINSR]

I spent my five minutes out there tonight leveling the cab and front end. They were a bit off and I have them perfect now.

Ready to start on the hood.

Brian

[MARTINSR]

Just a funny random post here. I was just in the break room at work and I noticed this Street Rodder magazine from 1995 with the Oakland Roadster show mentioned on the front page. I know I was involved with a car or bike or something about every year at the GNRS in the nineties and just opened it up to see if something I did was in there. It wasn't but this COE AD was and I remember it well, then I saw that in the back ground is the Model A I did all the body and paint on! LOLOL It came in first in it's class too!

Damn I had a lot of fun with that show, it's gone now, in SoCal hundreds of miles away.

Brian