How to handle this Rust? - Page 2 - Vintage Mustang Forums
 6Likes
Reply
 
Thread Tools
post #16 of 41 (permalink) Old 05-26-2016, 02:41 PM
Senior Member
 
Join Date: Sep 2005
Location: NJ
Posts: 2,898
Quote:
Originally Posted by Brian F View Post
For this same issue, I used poly carbide discs. They don't generate too much heat, don't grind down the metal, and leave a nice clean surface. I did go over the metal with 80 grit and then epoxy primer.
I like strip discs for small areas, but make no mistake, they are still an abrasive, and as such still remove metal (at a moderate rate).

As far as sanding in general, it's shortcoming is getting into corners and crevices.

'65 A-code coupe, T-10 4-speed, 8" 3.25 limited slip

Last edited by stephen_wilson; 05-26-2016 at 02:44 PM.
stephen_wilson is offline  
Sponsored Links
Advertisement
 
post #17 of 41 (permalink) Old 05-26-2016, 03:08 PM Thread Starter
Junior Member
 
68Mike's Avatar
 
Join Date: May 2016
Location: Peoples Republic of Massachusetts
Posts: 18
Garage
Riley I will PM you to pick you brain if that is alright. I'd like to thank everyone for input
68Mike is offline  
post #18 of 41 (permalink) Old 05-26-2016, 03:53 PM
Senior Member
 
Riley's Avatar
 
Join Date: Oct 2013
Posts: 1,095
Sure. I'm at work so I'm not doing anything right now haha!
Riley is offline  
 
post #19 of 41 (permalink) Old 05-26-2016, 03:59 PM
Senior Member
 
Woodchuck's Avatar
 
Join Date: Mar 2001
Location: Peoples Republic of Vermont
Posts: 33,153
Send a message via Yahoo to Woodchuck
What Pete says. EVERY manufacturer uses a bare metal prep (etch) prior to painting. This conditions the metal surface so that paint will stick as well as removes any mill scale or foreign ferrous metals. Yes, phosphoric acid is a converter and using it in conjunction with scrubbing and/or abrasion is really using it as two things, a medium to remove the iron phosphate residue and an acid etch to the remaining metal.

I, personally, use Picklex20 as a pre-paint prep as it contains a lower concentration of phosphoric acid and a proprietary formula that does not require neutralization after application and, after drying, can be directly coated.

Master Series Silver is, from everything I have heard, a decent product and can be sprayed, brushed or rolled on. I have never used it but may try it on one of my tractors in the future. I have used, exclusively, Eastwood/Kirker epoxy primer with good results. It can also be sprayed, rolled or brushed on. It sands well, too.

Bart

What, me worry?
- Alfred E. Neuman

Woodchuck is online now  
post #20 of 41 (permalink) Old 05-26-2016, 04:56 PM
PetesPonies
Guest
 
Posts: n/a
Quote:
Originally Posted by Riley View Post
Pete, somehow this seems to be turning into a pissing match of who's knowledge of surface prep is more vast. That was not my intention nor should it be yours.

You and others may have a different belief. But the phosphoric acid is to me a converter, not a remover. It turns the iron oxide into iron phosphate which, yes, is more stable but it's still there(unless some loose scale wipes off in the process).

If you have enough iron oxide on the surface to convert it into any negligible amount of iron phosphate then you are NOT done sanding.

I prefer two part catylized DTM epoxy over moisture cure 'pre-paints'. My question to you is (please give honest no BS answer) why use the Master Series? If the PA removes the rust as you say it does, what is the master series doing that a 2 part catylized DTM epoxy will not?

Edit: one more question: what do you coat directly over the MS?
First, don't tell me how I should think. That isn't your business. Second, you turned it into a pissing match when you downgraded my suggestions as unnecessary or incorrect way to handle rusted metal..
post #21 of 41 (permalink) Old 05-26-2016, 05:08 PM
Senior Member
 
Riley's Avatar
 
Join Date: Oct 2013
Posts: 1,095
How to handle this Rust?

Quote:
Originally Posted by bartl View Post
What Pete says. EVERY manufacturer uses a bare metal prep (etch) prior to painting. This conditions the metal surface so that paint will stick as well as removes any mill scale or foreign ferrous metals. .

While all manufacturers use a specific prep product I think it should be noted that they are not all created equal. SPI uses a water born W&G remover with a specific PH. It is not a muriatic acid based converter and they explicitly state not to use acid before using their epoxy. So not EVERY manufacturer uses etch. Metal prep yes.

PPG dplf epoxy can be sprayed using regular old dx330 w&g and does not require a converter if film build is adequate but does play nice with acid converters.

Many epoxies can NOT be sprayed over an acid etch primer for example ( zinc based).

The PH of the metal can be more temperamental to different brands than others. Kirker seems to be more resilient to acid from what you guys have said on the forums. SPI is not.

I was taught to rely on the mechanical bond of the epoxy to the 180 da crosshatch to clean metal and not to rely on a chemical bond. Soda blasted cars need to be neutralized in many cases as the PH of the metal is incorrect. You guys with kirker seem to have found it works well but I wouldn't lump all epoxies in saying they will all play nice with another prep/acid product.
Riley is offline  
post #22 of 41 (permalink) Old 05-26-2016, 05:27 PM
Senior Member
 
Woodchuck's Avatar
 
Join Date: Mar 2001
Location: Peoples Republic of Vermont
Posts: 33,153
Send a message via Yahoo to Woodchuck
Quote:
Originally Posted by Riley View Post
While all manufacturers use a specific prep product I think it should be noted that they are not all created equal. SPI uses a water born W&G remover with a specific PH. It is not a muriatic acid based converter and they explicitly state not to use acid before using their epoxy. So not EVERY manufacturer uses etch. Metal prep yes.

PPG dplf epoxy can be sprayed using regular old dx330 w&g and does not require a converter if film build is adequate but does play nice with acid converters.

Many epoxies can NOT be sprayed over an acid etch primer for example ( zinc based).

The PH of the metal can be more temperamental to different brands than others. Kirker seems to be more resilient to acid from what you guys have said on the forums. SPI is not.

I was taught to rely on the mechanical bond of the epoxy to the 180 da crosshatch to clean metal and not to rely on a chemical bond. Soda blasted cars need to be neutralized in many cases as the PH of the metal is incorrect. You guys with kirker seem to have found it works well but I wouldn't lump all epoxies in saying they will all play nice with another prep/acid product.
When I said "manufacturers" I meant AUTOMOBILE manufacturers, not COATINGS manufacturers. Also, when etching ferrous metals, it IS a mechanical bond, not a chemical bond. The etching provides a significant increase in surface area for bonding. Lastly, ALWAYS refer to the tech sheet for the products being used to ensure compatibility with each other.

Bart

What, me worry?
- Alfred E. Neuman

Woodchuck is online now  
post #23 of 41 (permalink) Old 05-26-2016, 05:36 PM
Senior Member
 
Riley's Avatar
 
Join Date: Oct 2013
Posts: 1,095
Quote:
Originally Posted by PetesPonies View Post
First, don't tell me how I should think. That isn't your business. Second, you turned it into a pissing match when you downgraded my suggestions as unnecessary or incorrect way to handle rusted metal..

I'm sorry you feel that way, Pete. I thought we could discuss like men but I see (read) that you are too upset to do that.

I didn't say your suggestion was wrong or incorrect. Just that in my opinion it was unnecessary to spray an entire car with rust encapsulator. The primer I spray doesn't do well with acids and I've never had a need to do that either to that extent (entire car).

I even asked you if you could elaborate (at least for the sake of discussion and the OP) but I guess not.
Riley is offline  
post #24 of 41 (permalink) Old 05-26-2016, 05:37 PM
Senior Member
 
Riley's Avatar
 
Join Date: Oct 2013
Posts: 1,095
How to handle this Rust?

Quote:
Originally Posted by bartl View Post
when i said "manufacturers" i meant automobile manufacturers, not coatings manufacturers. Also, when etching ferrous metals, it is a mechanical bond, not a chemical bond. The etching provides a significant increase in surface area for bonding. Lastly, always refer to the tech sheet for the products being used to ensure compatibility with each other.

+1

TOTALLY thought you meant coating manufacturers.

10-4

Last edited by Riley; 05-26-2016 at 05:39 PM.
Riley is offline  
post #25 of 41 (permalink) Old 05-27-2016, 12:12 PM
Super Moderator
Supporting Member
 
Israel's Avatar
 
Join Date: Feb 2011
Location: New Orleans
Posts: 8,766
I'm going with Pete here. After sanding down very thoroughly I can't see there Not being very small black spots of rust still imbedded in the metal. I know that I have them everywhere.

I agree that shooting the entire shell with MS is probably overkill,.........but that's what I'm doing.

Ex-wife,....."You drove how far for that thing?"
Daughter,..."Theres no inside and it stinks."
Friend,......."Dude, thatís a rusted pile."
Son,.........."This old car is cool."

USMC Security Forces, Kamiseya Japan, 0311

Build Thread: http://forums.vintage-mustang.com/vi...sted-pile.html
Israel is online now  
post #26 of 41 (permalink) Old 05-27-2016, 10:29 PM
Senior Member
 
Riley's Avatar
 
Join Date: Oct 2013
Posts: 1,095
How to handle this Rust?

I'll offer this. Last winter I had someone call me up to consult him on how to tackle the body work on his project. He's doing it himself but wants guidance. It's an old chev that had the bad primer from the factory. Super straight but lots of surface rust:

ImageUploadedByAutoGuide1464401160.179908.jpg

I told him to sand it with 80 on a DA and call me in three days. He asks me three days later what kind of product he can use to convert the surface rust. I say send me a pic:

ImageUploadedByAutoGuide1464401290.754755.jpg

At this point all he's used is a DA and he's concerned about the areas at the top of the box but he's convinced he's done sanding. I tell him at that point he's just smearing the oxidation around with your dirty disc and not getting rid of it. I say wipe it down with laquer thinner and use clean 80 grit discs and keep repeating.

He calls me a day or two later and asks is this clean enough? Are these black specks rust? (This is the top of the box from the above pic and the Lower door)

ImageUploadedByAutoGuide1464401490.967410.jpg

ImageUploadedByAutoGuide1464401501.036434.jpg

I say yes. That is surface rust. Switch to 180 grit and keep cleaning with laquer thinner. You are not done sanding yet. He keeps repeating until his sanding discs are clean and no residue is on the wipe-all and all that's visible is clean 180 crosshatch. Zero specks visible anywhere. Then switch to W&G remover and spray two coats of epoxy after masking/blowing down/ect.

I won't bore you with every detail but i guided him with gun setup and what/how to spray, sanding processes, ect.

ImageUploadedByAutoGuide1464402083.775327.jpg

ImageUploadedByAutoGuide1464402093.281127.jpg

This was a normal guy, do it in your garage paint job. Surgical cleanliness on bare steel with no acids or converters. He said he could have ate off the steel before he sprayed the epoxy. I told him after the epoxy he could roll it outside. It's weatherproof. The above pic is the final result of his first paint job.

In a nutshell that's the process I use and have had success with. Like it or hate it that's how I get the vehicle to the 'epoxy' stage.

Last edited by Riley; 05-27-2016 at 10:41 PM.
Riley is offline  
post #27 of 41 (permalink) Old 05-27-2016, 10:41 PM
PetesPonies
Guest
 
Posts: n/a
You do realize there is no such thing as a smooth surface. Every surface has grooves, pits, scratches, what have you. They are small and you can't see them.Ferrous Oxide lives in these areas too. I'm not saying paint ( which contains binders, "glue", in them} won't stick . . but for how long But I'm saying that it will stick better if there is no rust left. On an exterior piece of sheet metal, that is fairly easy to do, with a scrub of PA. So why leave it? I mean, you don't have a few more minutes to spend?
post #28 of 41 (permalink) Old 05-27-2016, 10:45 PM
Senior Member
 
Riley's Avatar
 
Join Date: Oct 2013
Posts: 1,095
How to handle this Rust?

Quote:
Originally Posted by PetesPonies View Post
I'm not saying paint ( which contains binders, "glue", in them} won't stick . . but for how long

Probably 50+ years if not exposed to a steady bath of salt on a garage kept car.

Last edited by Riley; 05-27-2016 at 11:38 PM.
Riley is offline  
post #29 of 41 (permalink) Old 05-27-2016, 10:55 PM
Senior Member
 
Riley's Avatar
 
Join Date: Oct 2013
Posts: 1,095
How to handle this Rust?

Quote:
Originally Posted by PetesPonies View Post
I mean, you don't have a few more minutes to spend?

The epoxies I spray have never specified acid and SPI in particular specifically says not to so its just something I don't do in most cases.

Once in epoxy the metal can't oxidize anymore. There is no moisture so whatever unseen oxidation left is stopped in its tracks and can't spread. Never lost sleep at night worrying about oxidization on the microscopic level using the above process.

Last edited by Riley; 05-27-2016 at 11:35 PM.
Riley is offline  
post #30 of 41 (permalink) Old 05-27-2016, 11:43 PM
Senior Member
 
Join Date: Jul 2009
Location: Niceville Fl
Posts: 4,593
Pete,

What prep do you do after spraying MS? What primer do you use on top of it? I have only used it once. I found it very hard to stir/mix. I tried brushing it on a floor and found it didn't brush well. It seemed to need thinning, but the packaged said it wasn't required. I am planning to spray the remainder to reach into hard to get areas. What do you thin it with to spray? What size gun nozzle do you use? What pressure? Thanks

Flade
68 289 convertible Candy-apple red & white
66 200 coupe Blue
94 GT convertible Red & black
98 GT convertible White & black
98 V6 convertible White & tan

Flade is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Vintage Mustang Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome