Bare metal time line
Thread Starter
Joined: Sep 2010
Posts: 35
From: ontario
Bare metal time line
Hey guys, I just started sand blasting the front end of my car, I'm going to do that in sections. My old man was a body man 20+ years ago, he tells me the bare metal will rust even after priming if not in paint soon....Just wondering what todays standards are...also ive read about primeing and sealing, but not sure what the difference is? I'm in southwestern ontario canada so its pretty humid in the summer but not bad in the winter. any insite is much appreciated, like steps, as in, sandblast, prime, scuff, seal, scuff, paint....or even what primers/sealers to use. right now im working on the engine compartment, then ill do the trunk and rear, then the interior then bottom.
thanks
Corzy
thanks
Corzy
4th Gear Member
Joined: Apr 2010
Posts: 1,027
From: NJ
Hey guys, I just started sand blasting the front end of my car, I'm going to do that in sections. My old man was a body man 20+ years ago, he tells me the bare metal will rust even after priming if not in paint soon....Just wondering what todays standards are...also ive read about primeing and sealing, but not sure what the difference is? I'm in southwestern ontario canada so its pretty humid in the summer but not bad in the winter. any insite is much appreciated, like steps, as in, sandblast, prime, scuff, seal, scuff, paint....or even what primers/sealers to use. right now im working on the engine compartment, then ill do the trunk and rear, then the interior then bottom.
thanks
Corzy
thanks
Corzy
4th Gear Member
Joined: Apr 2010
Posts: 1,027
From: NJ
Thread Starter
Joined: Sep 2010
Posts: 35
From: ontario
OK so i just read up on SPI epoxy primer and would like someone to explain it a little better please....looks like you just mix the primer and activator 1:1 then spray over bare metal that was sanded to 80 grit....it also says not to spray if under 60 degrees...has anyone used this in colder weather? also how do you prep the metal, is there a special cleaner to use, do you reduce the paint? also is that all i want to use, i plan on leaving it in primer for a while so i think it said to do 2 coats with a wait time in between spraying.
any tips would be great thanks
any tips would be great thanks
2nd Gear Member
Joined: Dec 2008
Posts: 386
From: Benicia, Ca
OK so i just read up on SPI epoxy primer and would like someone to explain it a little better please....looks like you just mix the primer and activator 1:1 then spray over bare metal that was sanded to 80 grit....
The 80 grit sanding gives tooth for the epoxy to "bite" into and stick
it also says not to spray if under 60 degrees...has anyone used this in colder weather?
Follow the tech sheets to the letter.
SPI epoxy Tech Sheet: http://www.southernpolyurethanes.com...oxy_primer.pdf
Lots of time and money was invested by the paint company to make them and to inform you with what works and what DOES NOT work. Low temperatures impact how the paint chemically reacts and dry.
also how do you prep the metal, is there a special cleaner to use, do you reduce the paint?
SPI recommends NOT using etch or any metal treatment. It is in the tech sheet for the epoxy. Mix the epoxy 1-1. Do not reduce unless you are using the epoxy for seal coat over high build primer and filler.
also is that all i want to use, i plan on leaving it in primer for a while so i think it said to do 2 coats with a wait time in between spraying.
SPI has a 7 day recoat window. This means you must apply another paint on top of it or you MUST rough the surface and shoot another coat of epoxy. The way around doing this is to shoot a High Build Primer on the epoxy within 7 days (or after waiting 60 minutes).You will need to do this anyway when you go to block out the car to make sure it is straight. It will save you lots of energy. High Build has NO recoat window.
For 2 coats of epoxy you need to let the epoxy "flash" off the solvents in it by waiting for 10-30 minutes between coats.
any tips would be great thanks
The 80 grit sanding gives tooth for the epoxy to "bite" into and stick
it also says not to spray if under 60 degrees...has anyone used this in colder weather?
Follow the tech sheets to the letter.
SPI epoxy Tech Sheet: http://www.southernpolyurethanes.com...oxy_primer.pdf
Lots of time and money was invested by the paint company to make them and to inform you with what works and what DOES NOT work. Low temperatures impact how the paint chemically reacts and dry.
also how do you prep the metal, is there a special cleaner to use, do you reduce the paint?
SPI recommends NOT using etch or any metal treatment. It is in the tech sheet for the epoxy. Mix the epoxy 1-1. Do not reduce unless you are using the epoxy for seal coat over high build primer and filler.
also is that all i want to use, i plan on leaving it in primer for a while so i think it said to do 2 coats with a wait time in between spraying.
SPI has a 7 day recoat window. This means you must apply another paint on top of it or you MUST rough the surface and shoot another coat of epoxy. The way around doing this is to shoot a High Build Primer on the epoxy within 7 days (or after waiting 60 minutes).You will need to do this anyway when you go to block out the car to make sure it is straight. It will save you lots of energy. High Build has NO recoat window.
For 2 coats of epoxy you need to let the epoxy "flash" off the solvents in it by waiting for 10-30 minutes between coats.
any tips would be great thanks
http://chris66dad.tripod.com/id22.html
http://chris66dad.tripod.com/id23.html
http://chris66dad.tripod.com/id24.html
http://chris66dad.tripod.com/id26.html
Hope this helps
Last edited by chris66dad; Oct 15, 2010 at 05:39 PM.
Thread Starter
Joined: Sep 2010
Posts: 35
From: ontario
- so, after sand blasting i dont need to DA to 80 grit since it will have enough rough surface to adhear to correct?
- Guess ill be tarping in the car with some heat lamps to keep the temp up for when i shoot.
- SO after sand blasting, just blow all the grit and dust off as best as possible and just shoot? no tak rags or anything?
- lastly, right now im working on the engine compartment, trunk, interior and under carraige/frame....so no block sanding will be done, do i still need to use the fill primer over the epoxy, or what is the more popular way to do these areas? is there a special undercoat paint, or just a cheaper version of the base/clear?
thanks for all the great tips.
- Guess ill be tarping in the car with some heat lamps to keep the temp up for when i shoot.
- SO after sand blasting, just blow all the grit and dust off as best as possible and just shoot? no tak rags or anything?
- lastly, right now im working on the engine compartment, trunk, interior and under carraige/frame....so no block sanding will be done, do i still need to use the fill primer over the epoxy, or what is the more popular way to do these areas? is there a special undercoat paint, or just a cheaper version of the base/clear?
thanks for all the great tips.
4th Gear Member
Joined: Apr 2010
Posts: 1,027
From: NJ
Wipe down with a degreaser and shoot. The blast should be more than enough. Also, I would not shoot anything over the epoxy. Just shoot 2 coats. When you're ready to do your body work block sand the epoxy, use a long board. When you find the low spots just rough it up with 80 - 120 and apply your filler. Check with SPI, most epoxies you can fill over but make sure you have the right one. When you're done with filler then shoot the whole car again with epoxy. Block sand then shoot with a 2K primer followed by your color.
Again, call SPI to make sure you can fill over their epoxy. I know I can with my Chromate Epoxy from Dupont. My chromate was also high build.
Also talk to SPI about temp. I've done structural fiberglass repair using epoxy resin in colder temp, just took a long time to cure.
I great things about SPI and their customer service.
Again, call SPI to make sure you can fill over their epoxy. I know I can with my Chromate Epoxy from Dupont. My chromate was also high build.
Also talk to SPI about temp. I've done structural fiberglass repair using epoxy resin in colder temp, just took a long time to cure.
I great things about SPI and their customer service.
2nd Gear Member
Joined: Dec 2008
Posts: 386
From: Benicia, Ca
- so, after sand blasting i dont need to DA to 80 grit since it will have enough rough surface to adhear to correct?
Are you using sand, media, walnut shells, or soda to blast? Each are different in how agressive they are. Be really careful with sand because it gets the metal hot and WILL warp it. I would recommend just hitting it with 80 grit after blasting to be sure the metal is roughed up. The 4 hours sanding will be worth it. The epoxy is the foundation for your paint. A rework will take LOTS more time to fix it. It will not take long to do it. Make sure you get all of the sand out. Shop vac will help along with compressed air.
- Guess ill be tarping in the car with some heat lamps to keep the temp up for when i shoot.
As long as the metal temp is 60 you are ok. Be really careful with heaters/heat lamps and painting. NEVER use a kerosene heater because it will put an oily film on the metal and the paint will fish eye or fail to adhere
- SO after sand blasting, just blow all the grit and dust off as best as possible and just shoot? no tak rags or anything?
Clean everything! I would use wax and grease remover first and then tack rag all parts before painting to eliminate dust.
- lastly, right now im working on the engine compartment, trunk, interior and under carraige/frame....so no block sanding will be done, do i still need to use the fill primer over the epoxy, or what is the more popular way to do these areas? is there a special undercoat paint, or just a cheaper version of the base/clear?
I would use a primer on top of the epoxy so you will not have to sand it and shoot epoxy again if you go past the 7 day window. The epoxy protects the metal and the primer will solve you 7 day window issue. Or you can shoot epoxy wait until your ready to paint, rough up the surface and shoot another coat of epoxy and then shoot a primer. Just more work later...
You can use a high build primer or regular primer. NEVER RATTLE CAN PRIMER!!!
SPI also sells primers http://www.southernpolyurethanes.com...ct%20lines.htm
For the under carriage, use epoxy and then use urethane truck bed liner. It comes in rattle cans at most auto parts stores. The epoxy will seal the metal from rust and the bed liner will protect the epoxy from rock damage
thanks for all the great tips.
Are you using sand, media, walnut shells, or soda to blast? Each are different in how agressive they are. Be really careful with sand because it gets the metal hot and WILL warp it. I would recommend just hitting it with 80 grit after blasting to be sure the metal is roughed up. The 4 hours sanding will be worth it. The epoxy is the foundation for your paint. A rework will take LOTS more time to fix it. It will not take long to do it. Make sure you get all of the sand out. Shop vac will help along with compressed air.
- Guess ill be tarping in the car with some heat lamps to keep the temp up for when i shoot.
As long as the metal temp is 60 you are ok. Be really careful with heaters/heat lamps and painting. NEVER use a kerosene heater because it will put an oily film on the metal and the paint will fish eye or fail to adhere
- SO after sand blasting, just blow all the grit and dust off as best as possible and just shoot? no tak rags or anything?
Clean everything! I would use wax and grease remover first and then tack rag all parts before painting to eliminate dust.
- lastly, right now im working on the engine compartment, trunk, interior and under carraige/frame....so no block sanding will be done, do i still need to use the fill primer over the epoxy, or what is the more popular way to do these areas? is there a special undercoat paint, or just a cheaper version of the base/clear?
I would use a primer on top of the epoxy so you will not have to sand it and shoot epoxy again if you go past the 7 day window. The epoxy protects the metal and the primer will solve you 7 day window issue. Or you can shoot epoxy wait until your ready to paint, rough up the surface and shoot another coat of epoxy and then shoot a primer. Just more work later...
You can use a high build primer or regular primer. NEVER RATTLE CAN PRIMER!!!
SPI also sells primers http://www.southernpolyurethanes.com...ct%20lines.htm
For the under carriage, use epoxy and then use urethane truck bed liner. It comes in rattle cans at most auto parts stores. The epoxy will seal the metal from rust and the bed liner will protect the epoxy from rock damage
thanks for all the great tips.
Last edited by chris66dad; Oct 15, 2010 at 08:22 PM.
Thread Starter
Joined: Sep 2010
Posts: 35
From: ontario
OK great i think i got it now...The epoxy goes on first but needs to be covered by something, and if done within 7 days, i dont need to re sand (since its the areas not seen other than the engine compartment thats a plus) so i can use spray cans for the bottom? I was told about a product from 3M called shultz, but dont know much about it, or how expensive it is.
thanks again guys, this forum is great
thanks again guys, this forum is great