Frame rustproofing, priming and topcoating
Thread Starter
Pro
Joined: Feb 2003
Posts: 655
Likes: 12
From: Texas
Frame rustproofing, priming and topcoating
I have thought about rustproofing my inside frame structure with a POR product before sandblasting. Let it cure out and then blast away the external, accessible rust. Reason for this is rustproofing after blasting, will probably have this goo run out over my now sandblasted exterior. Immediately after sandblasting I can prime and paint frame. Any thoughts or steps or products of what you all used will be appreciated. THANKS! :cheers:
Racer
Joined: May 2002
Posts: 431
Likes: 1
From: close to Frankfurt/Main Germany
Re: Frame rustproofing, priming and topcoating (vettnut)
I was using Mike Sander´s Korrosionsschutzfett over here in Germany. The product won about every contest I´ve ever had in my hands.
You will need approx 4 kgs for a complete frame. You will need some equipment as the wax is heated up to nearly 100 deg Celsius before blowing it into the frame. It really crawls into every corner....
http://mike.british-cars.de/english.htm
Read this....
[Modified by Mikey1, 7:55 AM 5/28/2003]
You will need approx 4 kgs for a complete frame. You will need some equipment as the wax is heated up to nearly 100 deg Celsius before blowing it into the frame. It really crawls into every corner....
http://mike.british-cars.de/english.htm
Read this....
[Modified by Mikey1, 7:55 AM 5/28/2003]
Racer
Joined: May 2003
Posts: 457
Likes: 0
From: Detroit Metro MI
Re: Frame rustproofing, priming and topcoating (vettnut)
One of the quandrys of restoration is choosing the right processes and materials to do the best and most professional job.
Rather than sandblasting, consider using the "Redi-Strip" process. It consists of full immersion in an alkaline bath to clean paint, grease, roadgrime, etc. and then an electrolytic derusting process which works in the reverse of plating, whereby iron oxide particles (rust) are drawn away from the metal. After the process the metal is treated with a water soluable temporary rust inhibitor to prevent flashing. What you end up with is a totally clean frame ready for priming and paint. The following experience is my own and is what I learned and did with my frame.
Initially I thought I could sandblast it myself. I had a hopper type sandblaster and a commercial sized air compressor. I soon found out that while adequate for cleaning small parts, this set up wouldn't work for such a large job. Not only would the amount of sand used be huge but it would take me a very long time. Since there was a commercial sandblasting operation nearby I took the frame there to be finished. I don't remember the exact cost but I think it was around $150. It came back nice and clean except for the inside of the frame rails which are unreachable by media blasting. I wanted to do those areas to stop any potential rusting there that might be going on.
I knew about Redi Strip but didn't think there was a facility near me, I lived in Florida at the time. I found a company called Revivation near Tampa, about 4 hrs away, that used the same process. I loaded up the frame and other parts I wanted to strip and clean and took them over. For comparison, current pricing with them is $36 pr ft on a frame. A C1 would cost about $500. You may have to do some searching to find a similar facility near you but it is worth a drive and the money if you do.
After stripping and cleaning, I used a product called Ospho. Ospho is a phosphoric acid based primer that reacts chemically with the surface of the metal to increase the adhesive properties of paint and forms a zinc oxide coating. It also offers some rust protection properties as well and will "kill" rust, converting it to an inert black substance. It is very popular in the marine industries and is sold almost everywhere paints are sold in Florida. You might have a hard time finding it in ND but Ace Hardware can order it for you. It is watery and is easy to brush or spray. After I started the job, I found that the Ospho reacted with the temporary rust inhibitor they used, turning it blue. So I washed the frame completely with soap and water and then blew it dry with an airhose. Then I wiped down all areas I could reach with a metal cleaner before applying the Ospho. I used a squirt bottle with a short hose attachment to squirt it into the frame rails. I also turned over the frame to make sure to coat all inside edges of the rails. After allowing it time to dry I then rinsed the frame again with water and blew it dry.
Make sure before painting that the frame is thoroughly clean and free from any residue left by the Ospho. For paint I used a self etching epoxy primer and finished with a semi flat-gloss black polyurethane. I am almost ready for reassembly so now I have to make a decision on what to do to further protect the inside of my frame rails. I am leaning towards taking the frame to a Ziebart rustproofing facility and letting them shoot it inside. Taping over the holes would minimize any overflow. Any of the undercoating that drips out could easily be cleaned up with a rag and mineral spirits while still fresh. I may experiment with POR 15 to see if I could control the application well enough to use it. Considering that the inside of the frame rails are protected, I am not sure what advantage POR 15 offers vs ease of application and cleanup of any overflow that a good rust prevention and undercoating process like Ziebart provides.
I know this is overkill and is way beyond what Chevrolet specified for manufacturing these frames. Initially they were dipped in an asphalt based black paint. Not the most durable coating but some restorations shops probably use this today as the only "correct" way to finish the frame. Sorry but not good enough for me when I can use a superior product and get the same look.
Most frames and sheet metal componenets today are ecoated before painting. If you have access to ecoating that would be the best way to go for "priming" as the frame is dipped and all surfaces are coated equally. Then follow up with powder coating or a good polyurethane paint. If I were doing my frame over today I think I would opt for powder coating vs. paint, even though it is more expensive. I don't think there are too many large frame sized tanks available for ecoating to the public but it is worth investigating. PPG might be able to provide you some names.
I hope my experience gives you some ideas. Stay away from acid dipping as this actually removes good metal along with the rust.
To learn more about alkaline and electrolytic stripping (Ready-Strip) check out the links below:
http://www.usmetalprocessing.com
http://www.americanmetalcleaninginc.com
http://www.revivation.com
[Modified by Solid327, 7:10 PM 5/28/2003]
Rather than sandblasting, consider using the "Redi-Strip" process. It consists of full immersion in an alkaline bath to clean paint, grease, roadgrime, etc. and then an electrolytic derusting process which works in the reverse of plating, whereby iron oxide particles (rust) are drawn away from the metal. After the process the metal is treated with a water soluable temporary rust inhibitor to prevent flashing. What you end up with is a totally clean frame ready for priming and paint. The following experience is my own and is what I learned and did with my frame.
Initially I thought I could sandblast it myself. I had a hopper type sandblaster and a commercial sized air compressor. I soon found out that while adequate for cleaning small parts, this set up wouldn't work for such a large job. Not only would the amount of sand used be huge but it would take me a very long time. Since there was a commercial sandblasting operation nearby I took the frame there to be finished. I don't remember the exact cost but I think it was around $150. It came back nice and clean except for the inside of the frame rails which are unreachable by media blasting. I wanted to do those areas to stop any potential rusting there that might be going on.
I knew about Redi Strip but didn't think there was a facility near me, I lived in Florida at the time. I found a company called Revivation near Tampa, about 4 hrs away, that used the same process. I loaded up the frame and other parts I wanted to strip and clean and took them over. For comparison, current pricing with them is $36 pr ft on a frame. A C1 would cost about $500. You may have to do some searching to find a similar facility near you but it is worth a drive and the money if you do.
After stripping and cleaning, I used a product called Ospho. Ospho is a phosphoric acid based primer that reacts chemically with the surface of the metal to increase the adhesive properties of paint and forms a zinc oxide coating. It also offers some rust protection properties as well and will "kill" rust, converting it to an inert black substance. It is very popular in the marine industries and is sold almost everywhere paints are sold in Florida. You might have a hard time finding it in ND but Ace Hardware can order it for you. It is watery and is easy to brush or spray. After I started the job, I found that the Ospho reacted with the temporary rust inhibitor they used, turning it blue. So I washed the frame completely with soap and water and then blew it dry with an airhose. Then I wiped down all areas I could reach with a metal cleaner before applying the Ospho. I used a squirt bottle with a short hose attachment to squirt it into the frame rails. I also turned over the frame to make sure to coat all inside edges of the rails. After allowing it time to dry I then rinsed the frame again with water and blew it dry.
Make sure before painting that the frame is thoroughly clean and free from any residue left by the Ospho. For paint I used a self etching epoxy primer and finished with a semi flat-gloss black polyurethane. I am almost ready for reassembly so now I have to make a decision on what to do to further protect the inside of my frame rails. I am leaning towards taking the frame to a Ziebart rustproofing facility and letting them shoot it inside. Taping over the holes would minimize any overflow. Any of the undercoating that drips out could easily be cleaned up with a rag and mineral spirits while still fresh. I may experiment with POR 15 to see if I could control the application well enough to use it. Considering that the inside of the frame rails are protected, I am not sure what advantage POR 15 offers vs ease of application and cleanup of any overflow that a good rust prevention and undercoating process like Ziebart provides.
I know this is overkill and is way beyond what Chevrolet specified for manufacturing these frames. Initially they were dipped in an asphalt based black paint. Not the most durable coating but some restorations shops probably use this today as the only "correct" way to finish the frame. Sorry but not good enough for me when I can use a superior product and get the same look.
Most frames and sheet metal componenets today are ecoated before painting. If you have access to ecoating that would be the best way to go for "priming" as the frame is dipped and all surfaces are coated equally. Then follow up with powder coating or a good polyurethane paint. If I were doing my frame over today I think I would opt for powder coating vs. paint, even though it is more expensive. I don't think there are too many large frame sized tanks available for ecoating to the public but it is worth investigating. PPG might be able to provide you some names.
I hope my experience gives you some ideas. Stay away from acid dipping as this actually removes good metal along with the rust.
To learn more about alkaline and electrolytic stripping (Ready-Strip) check out the links below:
http://www.usmetalprocessing.com
http://www.americanmetalcleaninginc.com
http://www.revivation.com
[Modified by Solid327, 7:10 PM 5/28/2003]
