POR15 - Before I Paint Question

[S4Cruiser]

Before I crack open the can of POR15 and paint the frame on my 40 I had a quick question for those that have used it before. I searched but didn't find the answer I was looking for...

I've already wire wheeled and sanded, cleaned with TSP and brushed on Ospho. As designed, the Ospho created a grayish/white chalk where the rust spots were.

My question is, do I need to remove the residue left over by the Ospho (scuff it off with a scotch bryte pad and vacuum off any dust left over) or just paint over it with the POR15.

I want to get this right the first time and not f up something that I'm spent significant time on so far.

I'll be sure to post up pics once I'm finished.


-Jon

 

[bsmith123]

POR

ref this web site page---looks like you just brush it off


Icon International - Products

OSPHO is a rust-inhibiting coating - NOT A PAINT You do not have to remove tight rust. Merely remove loose paint and rust scale, dirt, oil, grease and other accumulations with a wire brush - apply a coat of OSPHO as it comes in the container - let dry overnight, then apply whatever paint system you desire. When applied to rusted surfaces, OSPHO causes iron oxide (rust) to chemically change to iron phosphate - an inert, hard substance that turns the metal black. Where rust is exceedingly heavy, two coats of OSPHO may be necessary to thoroughly penetrate and blacken the surface to be painted. A dry, powdery, grayish-white surface usually develops; this is normal - brush off any loose powder before paint application.

I cleaned it off mine before I painted. POR likes tooth so dont be afraid to rough it up a little. The por flows out looking almost like a candy shell. search on storing POR there are some good ideas to keep it useable

If you are painting it on with a brush or rolling it on follow with very light top stroke with a foam brush for a really smooth finish
("roll and tip method")

some pics of my tub POR'd in my build link pg 1, post 3 &4 --see the sig line

 

[rsc71]

i cleaned mine off just in case

 

[S4Cruiser]

Cool - that's what I figured but wanted the MUD consensus JIC.

-Jon

 

[thecrazygreek]

Just an fyi, never open a can of POR 15. Poke a hole with a screwdriver, and seal with tape when done. It will last a LOT longer that way.

 

[76FJ40]

Just an fyi, never open a can of POR 15. Poke a hole with a screwdriver, and seal with tape when done. It will last a LOT longer that way.

Storing opened POR or Rust Bullet in the refrigerator will also keep it from setting up for a loooong time. I've kept opened POR containers in the fridge for at least a couple of months.

 

[JohnnyC]

I remember hearing that you should put saran wrapbetween the can and lid...that will also help keep it and be able to open it again later?

anybody find that thats true?

 

[makomark]

I remember hearing that you should put saran wrapbetween the can and lid...that will also help keep it and be able to open it again later?

anybody find that thats true?

I used the saran wrap and it worked, although the screw driver method would seem to be better. Also buy the POR 15 by the quart and not the gallon. I would also remove the ospho first but I would think using steps one and two of the POR 15 pretreatment would remove the ospho anyway.

 

[IH8Wood]

I followed their directions and got very good results: "First use Marine Clean to clean and degrease the surface, when clean rinse with water and allow area to dry. Second spray Metal Ready on surface full strength, keep wet for 15-20 minutes then rinse with water and allow to completely dry." Elsewhere the say "Make sure surface to be painted is bone-dry. Use a hairdryer if necessary."

 

[bsmith123]

TSP and OSPHO

TSP and OSPHO are suitable substitutes for Metal Prep and Aqua Clean only a lot cheaper and you can get them at ACE hardware so you dont need the POR stuff if you use these

TSP is tri sodium phosphate--comes in a package to mix with water ---super concentrated

Pokin a hole in the can and using tape---That's the great idea I keep forgetting!

 

[S4Cruiser]

TSP and OSPHO are suitable substitutes for Metal Prep and Aqua Clean only a lot cheaper and you can get them at ACE hardware so you dont need the POR stuff if you use these

Yep - from what I've read, Metal Ready is simply Phosphoric acid just relabeled with POR's procudt sticker. Ospho is phosphoric acid.

 

[73fj40lc]

Ospho and POR15

I have got ospho and POR15 for my M101 CDN trailer. I have heard the the POR15 is good as a finish layer as long as it is not subjected to sunlight / UV. Is this true or do you prefer some other top coat to protect the POR15? I agree I don't want to make any mistakes. I want to kill the cancer once and for all.

 

[bsmith123]

top coat

The UV affects the appearance but not the protection but there are two ways you can go. Primer over the POR using POR TOP COAT PRIMER then paint with any paint or just go over the POR with POR's Chassis coat which can be painted straight over the top of the POR and is a semi gloss black

in my tub I did por-15 then top coat primer then singlestage polyurethane then Durabak and it all stuck just fine

 

[73fj40lc]

Any scuffing or sanding between the coats?