Cadillac & LaSalle Club Discussion Forum

Cadillac & LaSalle Club Forums => Technical / Authenticity => Topic started by: Mike Wenrich #1666 on October 08, 2015, 08:26:24 PM

Title: Painting Brake Backing Plates
Post by: Mike Wenrich #1666 on October 08, 2015, 08:26:24 PM
I have the backing plates off my 41 and will sand blast then paint them.  Raises the question.....do I paint the inside black as well as the outside.  Seems in the past I have not seen the inside painted.  Just bare metal.  So maybe paint is not good on the inside and just a high temp clear or gray spray would be better.  Any thoughts appreciated.

Mike
Title: Re: Painting Brake Backing Plates
Post by: Bobby B on October 08, 2015, 08:41:19 PM
Mike,
Hi. Black Epoxy primer the whole plate. You don't have to paint the inside. Whatever clear you spray on will most likely peel off. Epoxy is way tough…..
                                                                                                                                                                                                                       Bobby
Title: Re: Painting Brake Backing Plates
Post by: Mike Wenrich #1666 on October 09, 2015, 11:03:38 AM
I was thinking about the POR 15 I have been using as a rust encapsulator before painting anything on the undercarriage.  It's hard as nails but I am not sure the inside of the plate should have that kind of surface.  I like the idea of a hard primer though for the interior of the plate and drum.  Should be heat resistant as well.  I don't plan to drive this car in a lot of wet weather but you never know what you might get caught in when driving longer distances. 
Title: Re: Painting Brake Backing Plates
Post by: 76eldo on October 09, 2015, 10:36:00 PM
I'd use a thin coat of chassis black which can go over bare steel just to keep it from rusting on the inside. That's what I'm planning to do on the car I'm working on.

Brian
Title: Re: Painting Brake Backing Plates
Post by: Bobby B on October 09, 2015, 10:37:30 PM
Quote from: Mike Wenrich on October 09, 2015, 11:03:38 AM
I was thinking about the POR 15 I have been using as a rust encapsulator before painting anything on the undercarriage.  It's hard as nails but I am not sure the inside of the plate should have that kind of surface.  I like the idea of a hard primer though for the interior of the plate and drum.  Should be heat resistant as well.  I don't plan to drive this car in a lot of wet weather but you never know what you might get caught in when driving longer distances. 

Mike,
  Hi. I use epoxy primer for a base on all my engines for years, so I would think it would hold up to your braking needs. One piece of advice regarding POR-15. Stay Away! Nasty product with NO redeeming qualities. I used to use that stuff religiously years ago, till I found out what it was all about. I also had the convenience of living 10 minutes away, so it was an easy sell. Threw every can away, and lived happily ever after!  Epoxy is the way to go, and I've been using Southern Polyurethanes products for years, and they rule over other  high end, name brand primers I've used that cost 4X the price. Try it, you'll be glad you did!
                                                                                                                                                                                                                                                                  Bobby
Title: Re: Painting Brake Backing Plates
Post by: Mike Wenrich #1666 on October 10, 2015, 11:20:43 AM
Bobby....Can you be more definitive about the POR 15?  Maybe what you found out?  I used some of this already on the undercarriage and inside the wheel wells and would like to know if I need to go back over those areas.

Mike
Title: Re: Painting Brake Backing Plates
Post by: Bobby B on October 10, 2015, 12:30:57 PM
Mike,
  My take on POR-15….
1. Sometimes the easy way out and will only come back to bite you in the A** at a later date.
2. Will most likely peel in sheets if not properly prepped at a later date causing all sorts of headaches. I've seen it peel even when prepped correctly. The prep can be difficult in tight spots underneath a vehicle and usually involves rinsing.
3. If you don't use the whole can at once, you basically wasted a lot of money, and it isn't cheap. I've re-sealed the cans with all different methods and it will usually go bad no matter what you do, if you let it sit for any amount of time. It will harden in the presence of air, so don't leave the can open.
4. Don't get it on you (or your clothes), unless you want to wear it off. Takes about a week or two.
5.Once you paint something with it, good luck getting it off, (if it sticks). It will come back to haunt you because you say that you'll never re-do that part again and we all say that. When you go to re-do that part at a later date, you'll be swearing at the fact that you did it. Takes a lot of time  to get off in a blast cabinet with 60-80 grit aluminum oxide. Not Fun.
6. There are way better products out there with options, for a cheaper price.
7. The fumes are super Toxic. Do your homework regarding this. Not to be used in a closed or confined space, like a heated garage in the winter, unless you like a cheap high along with a sick stomach.
Do I need to continue?  ;D  Just my opinion though……
                                                                       Bobby
                                                                         
Title: Re: Painting Brake Backing Plates
Post by: Mike Wenrich #1666 on October 10, 2015, 04:33:18 PM
Points well taken and thank you. 

I have experienced many of them already but I prepped the areas painted very well so I hope the results will be good.  And I found the product in small cans (six of them to an order) so that I would not lose the product as you stated.  Been there, lost that.  I now wear heavy protective gloves when I use it but have not figured out how to get the second glove off after painting without getting at least some of the stuff on one hand.  Lacquer thinner works well to get the stuff off.  I put it on with a throw away brush and find that it runs easily and takes a long time to dry.

The primer you mentioned.  Is it a two part primer or premix?  Might be stupid question but there are soooo many products out there, it seems I have seen primer labeled epoxy.
Title: Re: Painting Brake Backing Plates
Post by: Bobby B on October 10, 2015, 06:20:02 PM
Mike,
Epoxy primer is a two-part, 1:1 mix, one-part epoxy, one-part activator.
                                                                                            Bobby

http://www.southernpolyurethanes.com

http://media.wix.com/ugd/8ced3e_1e5c47ba23dd43a7a35310ee9f969705.pdf
Title: Re: Painting Brake Backing Plates
Post by: Mike Wenrich #1666 on October 11, 2015, 12:29:38 PM
Thanks again for the links and information.  I was surprised to see that you apply the epoxy before body fillers.  This is really different stuff than I am accustomed to and I would have to call to see if they can ship to California.  We live in very governed territory here.  For the hobbyist, it may be difficult to use in the winter since product and bare metal need to be at or above 65 degrees.  Heading into fall I am okay now but soon would not be able to use the product. 

I am interested in their final coats but paint matching for the 41 would be a problem.  Trying to find something here is also a problem.  I primered the inside of the backing plates yesterday after sand blasting and I noticed that I could hardly strip the black paint I applied years ago off the back.  I am thinking it might be the POR 15 or something similar I used all those years ago and might be the problem you referred to.  It stuck well but brake fluid dissolved it and now I had to deal with sanding and then blasting to get it off. 

Mike
Title: Re: Painting Brake Backing Plates
Post by: Bobby B on October 11, 2015, 01:20:15 PM
Mike,
Hi. When doing a body-off, the first thing I do right after the car is stripped is to apply Epoxy primer to seal off the metal. Bodywork and all goes on top of it. Whole different world now. Filler on bare metal will usually bubble over the years from moisture getting under/in it.  Years ago, cars would be stripped and the shops would take weeks or months ( or years?) before all the metal work and fillers were done, and the car put in final primer. So all that bodywork and metal was exposed to some form of moisture getting to the final stage of sealers/primers and paint. Technology has come a long way even in the process of restoring a car.
                                                                                                                                                                                                                  Bobby
Title: Re: Painting Brake Backing Plates
Post by: Caddy Wizard on October 13, 2015, 10:49:57 AM
Best bet is to epoxy the outside and leave the inside unpainted.