TheSamba.com :: View topic - POR-15 Tie Coat Primer is crap, yes or no.

Mon May 16, 2011 6:17 pm

Used it twice. Both times followed directions to letter. Allowed plentiful cure times in dry climate indoors. Both times over POR 15, and product crinkled and cracked on applying topcoat.

Crap product in my opinion. Discuss.

Mon May 16, 2011 7:00 pm

I am not a bodywork expert but spend a ton of my personal time experimenting with new products to battle decay of our beloved vans.

This product is one of the layers of "POR15" rust encapsulation and is intergral if you with to use modern paints to layer over it.

I have used it with great success.
I let it flash for 15-20 minutes and lay my next spray right over it.

Pretty much how I layer all "rust" paint products.

I do heat cure locally to help set multiple layer areas.

Rock solid.

If I start with POR products I use all of them in multiple layers, light coats, flashing between each.
POR products, bodywork wise well for me but I have other favorites for chassis and suspension coatings.

Using a Tie Coat is not needed with some of the other vendors of "rust" paints.

Mon May 16, 2011 8:08 pm

I just had my first try at POR 15 to treat my rust. I had done rust repair a couple of years ago with Rust Mort or something similar and the rust was back within a year. I've heard such great things about POR 15 that I thought I'd give it a try. I did have a couple of small areas that sorta bubbled up a little when I put on the POR 15 layer but I sanded it back down and re-applied. Seems OK to me. I'm guessing the only way I'm truly gonna get rid of the rust is to cut out the rear quarter panels as some here have done to really get in there and eliminate all of it. I think it's in there deep and I'm only doing a temporary repair.

BTW insyncro, whadaya mean by 'flash?' I'm not a body and paint guy but I've heard this term used with regards to paint.

Tue May 17, 2011 5:01 am

Flash means allow the solvents to evaporate.

Tue May 17, 2011 5:11 am

psych-illogical wrote:

BTW insyncro, whadaya mean by 'flash?' I'm not a body and paint guy but I've heard this term used with regards to paint.

Thanks for asking, I didn't know that term as well.
I just finished my '66 Singlecab -lots of metal replacing, lots of POR 15.

Tue May 17, 2011 5:56 am

This is helpful, thank you insynchro.

Obviously, i was a bit perturbed when I made the original post. I will try it again, more coats with flashing in between, not necessarily full curing (24-48 hours) between.

Tue May 17, 2011 6:16 am

I have been using this stuff and it works great.
Sorry about the crazy video.

http://www.magnetpaints.com/underbody.asp

Tue May 17, 2011 6:51 am

Alaric.H wrote: I have been using this stuff and it works great.
Sorry about the crazy video.

http://www.magnetpaints.com/underbody.asp

If you are doing bodywork and fillers will be used, I do not recommend Magnet paints.
But yes they are good for suspension and chassis parts.

Tue May 17, 2011 6:53 am

SoonerDave wrote: This is helpful, thank you insynchro.

Obviously, i was a bit perturbed when I made the original post. I will try it again, more coats with flashing in between, not necessarily full curing (24-48 hours) between.

Temp and humidity level have a big part in how the products work.
I can not give an exact number for each to be perfect.
Just experiment and always do a small test spray first to make sure everything is kosher.

Tue May 17, 2011 7:15 am

I've been planning on trying the "Rust Bullet" product that's a banner advertiser here on Samba. Looks to be a very similar "rust converter and encapsulation" product just like POR-15. They show some direct testing against POR-15 and claim their product is even better.

Tue May 17, 2011 7:18 am

James 93SLC wrote: I've been planning on trying the "Rust Bullet" product that's a banner advertiser here on Samba. Looks to be a very similar "rust converter and encapsulation" product just like POR-15. They show some direct testing against POR-15 and claim their product is even better.

I have used it and had good results.
The POR products worked better if a lot of filler, putty or glazing is used.
I spray very light coats over fillers to get it to adhere well and than heavy layers over that.

Tue May 17, 2011 8:45 am

Interesting the only reason to use the tie coat is to allow a bond between the topcoat & the por 15 base coat that dries like ceramic

I have used both tie coat
simply waiting till the por 15 base coat is finger print tacky
then using any of the good quality autobody high build primers

in both cases work i did 4-5 years ago is till good to go
although I prefer the tacky then multiple light coats of high build primers
since the primer & the base15 seem to bond better than the etch of the the tie coat going on a cured por 15 base...

Tue May 17, 2011 10:04 am

tclark, that is also very helpful, thank you.

For the record, I have also been using Master Series Silver as a primer on locations where I did not use PO-15, and it has resulted in wonderful results. It is similar to rust bullet. Sanding it can be a bit of a bitch, but the topcoat I use goes onto it very easily.

Wed May 18, 2011 7:41 am

I used POR15 as a band-aid for surface rust on a '68 Intl. It has been on for about 8yrs. It likes to flake off. I like the 'ceramic' look but prefer Zero-Rust which is just a paint vs. a 'coating'. (POR is Black/Zero-Rust White in this pic)

I typically either wire brush or sandblast, then treat with PORs Metal Prep. I do the same thing with Zero-Rust. I'm sure whatever you do is better than watching it crumble into a pile of Orange, but this is my experience.

Jim

Wed May 18, 2011 10:09 am

Bitchin' interior, Wetstuff! What kind of car is that?
If Zero Rust is anything like Masterseries (I'm pretty sure their formulas are almost exactly the same), then I say go with it over POR 15. I tried POR 15 on my freshly sand blasted pans and it still flaked off. Masterseries silver on my blasted pans have taken falls, whacks with a sledge, and is a bitch of wire wheel and sand off. Love the stuff.

Wed May 18, 2011 7:00 pm

I just finished using the tie coat and had no problem with it other than it does like to run. I brushed it on since I planned on using 3m body shutz for the final coat. I started with por 15 on the bottom of my pan and wanted to put a topcoat over to add uv protection. I then added the tiecoat which I would recomend spraying it instead of brushing it and then sprayed eastwood epoxy primer and finished off with a coat of ceramic chasis paint. There are some runs underneath but not too bad and had NO problems adhering to the por 15. Sounds like you have a bad can of tie coat. Tie coat is made to bond chemically with por-15 so for it to crack and curtle doesnt make sense.

Thu May 19, 2011 8:45 am

Vinn, It's an Intl. Travelall, '68. My wife picked the fabric. This was before many of you were born - the cutsy, farm-look was in. Internationals, especially in the East, have a habit of collapsing like a stack of Orange cards if you do not stay ahead of the rust.

A great tool is a $40 sandblaster on Ebay that looks like a plastic box. It uses $3bag play sand and blow the s__t out of surface rust - while coating everything within 100yds.

Jim

Mon Aug 29, 2011 10:27 am

Por 15 is good for coating over rust, BUT, proper prep is essential. Clean the surface very well. Remove all residue of anything like oil, grease, wax etc. Even if you think sanding, blasting and wire brushing has left a raw metal surface, POR wont bond well. You must use degreaser and laquer thinner so the metal is absolutly clean. Then use an acid etch, like 'Metal Ready' and rinse again with water and a clean rag. Dry with a a strong fan, and/or leaf blower. Now the metal is ready to receive the POR15.

A single coat of Por15 works OK. Applying a second coat while the first coat has "finger drag" will work, but it will leave a 'blotchy' finish. Once the first coat is dry, a second coat will not bond well without scuffing and priming. Once the POR is fully cured, at least 3 days, use a self etching primer, then topcoat. POR 15 Tie Coat is probably not necessary.

Of course, I could be wrong about all this. But... Maybe you can learn from my experience. My first application of Por15 did not bond well. And heavily rusted areas 'bubbled-up.' I had to remove it all and start again. (By the way, Citrus Orange type paint stripper removes POR PDQ.)

Bottom line: grind of as much rust as possible, etch with acid (metal ready) treat remaining rust with Rust Mort, degreese throughly, rinse off residue of cleaners, dry throughly. Apply POR15 in single coat. Prime. Topcoat. It's a lot of work, BUT it will pay off in keeping your baby from rusting into oblivion.