bjhines Posted July 27, 2006 Share Posted July 27, 2006 I have both... I thought The Ospho would get into nooks and crannies and between layers of sheetmetal better than POR15.. I got a can of POR15 to handle areas that get chips and scrapes because I have heard it is incredibly HARD when cured... The problem I am having is that the instructions for POR15 say not to apply over rust converters... as far as I know the Ospho is considered a rust converter... The question is.. should I carefully apply the POR15 to all the areas I want to cover with it and let it cure completely... and THEN coat the rest of the bare metal body with OSPHO??? or the other way around.??? The body is sand blasted to bare metal.. no rust at all... Quote Link to comment Share on other sites More sharing options...
JMortensen Posted July 27, 2006 Share Posted July 27, 2006 If you're at bare metal I'd just POR15 it. Ospho is specifically for treating rust, which you're specifically saying isn't a problem in your case because it's been sandblasted. Quote Link to comment Share on other sites More sharing options...
skipzoomie Posted July 27, 2006 Share Posted July 27, 2006 NO OSPHO!!!!!!!!! The supplier you purchased the POR-15 from should have given you a sheet of directions. And yes, the OSPHO is a rust converter. Quote Link to comment Share on other sites More sharing options...
bjhines Posted July 27, 2006 Author Share Posted July 27, 2006 well... the POR15 website describes using their cleaner, their rust dissolver, THEIR RUST CONVERTER, and then POR15 on top of it all... and then using THEIR primer and their chassis paint over all of that... They even suggest using THEIR solvent for thinning and cleanup...... Im no spring chicken.. they are using the same chemicals that other maufacturers use in other products... they just want to sell me all of their high $$$ crap... I'll use the product.. but I'm not going to buy 3 times as much $$$ "stuff" as originally planned... but I was interested in information that could clear up what is actually necessary, and what is BS sales tactics... The OSPHO works as a prep coat using Phosphoric acid to convert the steel surface into Iron Phoshate to effectively seal the metal from O2.. OSPHO uses a different chemical reaction to achieve the same result as POR15.. the only thing about OSPHO is that it is not a HARD COATING... and it must be primed and painted to prevent it from developing a flash of white powder every time the humididty rises... To reiterate.. the entire car will get sprayed with OSPHO... but I wanted to coat the floorboards and sills with POR15 to provide a scratch resistant hard coating under my final paint Quote Link to comment Share on other sites More sharing options...
daveshybridz Posted July 27, 2006 Share Posted July 27, 2006 i say no to ospho, its a sticky mess.try some on one spot and you will see , it dont go on smooth, cause your trying to cover up rust and hard to get back off. get the metal prep that you use like soap and water and wash the bare metal and let air dry, then use a paint thinner to clean it after it dries. if your at home do one section at a time Quote Link to comment Share on other sites More sharing options...
bjhines Posted July 28, 2006 Author Share Posted July 28, 2006 hmm... I'll have to try some ospho on some scrap steel tonite... I was under the impression that it dries to a dusty surface with some white powder that must be brushed off before priming and painting... The instructions mention that this dusty white flash will keep comming back until it is covered in paint. Quote Link to comment Share on other sites More sharing options...
mikeatrpi Posted July 28, 2006 Share Posted July 28, 2006 You have to wash the ospho and residue off after you apply it. If you don't, it gets sticky and paint doesn't adhere. Ask me how I know! Quote Link to comment Share on other sites More sharing options...
Brad-ManQ45 Posted July 29, 2006 Share Posted July 29, 2006 A good scrubbing with a Scotch pad and you're good. I personally am using Zero Rust instead of POR. Much less, no iso's, easier to apply - go to the AutobodyStore Forums and see what people's experiences are. RacerX here at HybridZ is a big proponent of it - uses it on his personal cars as well as any customers' that are not adamant about using POR. I use OSPHO on all my welding areas to make sure I have no rust, after cleaning with Acetone, after grinding/sanding. Yes, I am anal.... Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.