Use SPI on top of POR15?

K

killervette

So i am working on a 67 mustang. I have the roof off and there is some pitting and surface rust on the frame structure. I can sand off alot of the surface rust, but not the pitted area. What is the best way to handle the pitting. I have a spot blaster but i dont think I can get everything with it.

Can i spray the area down with por 15? Then should i use SPI over top of the por 15?

Thanks. Here is a picture of the area I am referring to.

IMG_1723.jpg
 
You can't rinse that area, so it needs to be media blasted. From the looks of that rust and where it is, you are sure to need other areas on the car blasted as well. I would get all the rusty areas exposed and then find someone to do it or rent one.
 
I've never used one so I can't say.But check the price on blasting in your area. Around here I can have an entire truck frame blasted for around $200. Factor in the cost of the tool, blasting media, and your time and energy spent and It may be cheaper in the long run to have someone else blast it for you.
 
I thought about that, but the car is on jack stands with no wheels. Not sure how much of a pain it would be to get it to the blaster
 
Sandblasting is dirty and very messy job if you do not have the place or equipment. I have a small siphon style blaster that works similar to the one in your link and won't buy another one. It takes forever when the tip only removes a 1/4" spot and the siphon action either runs out of media or gets plugged.
Pressure blasters are the way to go for a portable at home type usage.
If you can get it blasted somewhere for a reasonable price I would say go for it. I built a roll about stand for my car that fastens to the bumper mounts on the frame rails. Bought some used scaffold wheels and the rest was scrap metal.
Once you get the shell back from the blasters cover with two coats of unreduced epoxy.
 
The car was media blasted before i bought it. They didnt have access to the areas under the roof skin and such. I bought the little blaster i referenced above and will give it a try. I have a pvc frame to hang plastic from to try and keep the mess down. Thanks!

Can i spray spi on top of another primer by just roughing it up with some 160 first?
 
As long as its completely cured it should be fine. Just remember the adhesion to the metal in those areas will be based on the other primer.
Also remember you can brush SPI epoxy into the crevices and other areas where a spray gun won't reach.
 
killervette;20912 said:
Would something like this work well?

http://www.amazon.com/Campbell-Haus...D1C4/ref=sr_1_3?ie=UTF8&qid=1338464813&sr=8-3
Click to expand...
Killer,

It'll work but how well depends on a couple of things. I bought the Sears version of that blaster 30 years ago and it sorta works. You have to use absolutely dry blasting media. If you use play sand it clogs in less than a minute (trust me). It also blasts a quarter-size area in about five seconds so the area you show in that picture will probably take at least an hour with two or three refillings of the container. According to Campbell-Hausfeld's site, the gun requires "9.0 average SCFM at 90 PSI" so you need a good size compressor to run it continuously. You'll spend a lot of time waiting for the compressor to catch up if yours is less than a 5hp unit. Even if your compressor is big enough, the setup has to put out very very dry air or you'll spend a bunch more time un-clogging the gun every few minutes.

A final piece of advice. When you get the urge to throw the thing across your shop, it's a good idea to empty the sand first -- reduces the severity of the damage to whatever it hits.
 
Haha....ok, good to know. I have a 60 gallon compressor that will do 15cfm or so. I will use a oil/water separator for the moisture. I will be blasting with black diamond media. This is beginning to suck! :)
 
Bob Heine;20926 said:
Killer,

It'll work but how well depends on a couple of things. I bought the Sears version of that blaster 30 years ago and it sorta works. You have to use absolutely dry blasting media. If you use play sand it clogs in less than a minute (trust me). It also blasts a quarter-size area in about five seconds so the area you show in that picture will probably take at least an hour with two or three refillings of the container. According to Campbell-Hausfeld's site, the gun requires "9.0 average SCFM at 90 PSI" so you need a good size compressor to run it continuously. You'll spend a lot of time waiting for the compressor to catch up if yours is less than a 5hp unit. Even if your compressor is big enough, the setup has to put out very very dry air or you'll spend a bunch more time un-clogging the gun every few minutes.

A final piece of advice. When you get the urge to throw the thing across your shop, it's a good idea to empty the sand first -- reduces the severity of the damage to whatever it hits.
Click to expand...

Best answer so far Bob! Those syphon blasters will piss you off more than anything else, x2 with the sears version ):
 
You must log in or register to reply here.
Back
Top