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2wrench

2wrench

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Cold. Wet. Rainy. Sucks for doing car work.
Lazy (engine parts still being machined). Little
excitement.

So, let's tell some stories (no lies).

Auto paint shop wanted $3,000 to replace rocker panels
on my '69 Chevy truck. POR-15 paint and fiberglass
for about $60 did the job...$30 a side.... not $1,500.

Been a couple years. No sign of problems yet.

I figured nothing from nothing leaves nothing, right?

Had a guy with the pan in a swamp cooler rusted out.
$450 for replacement cost plust the cost to install.
POR-15; fiberglass and paint. Claims a few years
of use later and no sign of problems.

My kids used to step onto the "dash" area of our ski
boat on the way to the bow to pull the anchor. They'd
sometimes step into the "glovebox" area where the
stereo resides. Cracked the plastic housing.
Stereo was about to fall out. POR-15 and fiberglass
and you'd have to look two, maybe three times to
recognize there was a problem. Kids been traversing
the area ever since. I conclude stronger than was, because
I have not had the problem recur (or maybe they learned).

My '91 Astro van was peeling paint. Typical problem.
Sealed with POR; covered and worked at restoring paint,
short of the thousands of dollars autobody shops insisted
needed be spent becuase the primer was bad.

Not to end on a bad note: But, I did use the POR stuff
on the body of my '69 truck. Worked poorly. Paint is
peeling; cracking and looking real bad. I conclude
a number of issues: Paint shot in winter with too much
precipitaiton; mixing of paint products; products not
curing thoroughly (I think this last was the greatest
problem.)

I have had POR spill and dry in places I really didn't
want it. The stuff is very, very hard.

In a thread recently the question was asked: Can you
sandblast POR off? An answer was: Yes, but with some
difficulty, or words to that effect (not an exact quote,
here.)

This last paragraph, I think, is testament to the
longevity of the material.

Tell me about your experiences. I know there is far
more to share.

Oh, and by the way, if I painted a surface with POR
and saw any amount of rust, I think I'd just paint it
again and keep on going. Far too easy. Far too cheap
to ignore.

What have you to add, if anything?
 
Don't know the long-term situation, but here's my POR15 tale about "holy" floorpans:

https://www.britishcarforum.com/bcforum/u...true#Post306219

Floorpans with holes, pinholes, and surface rust. Vacuumed up the loose stuff, sprayed with phosphoric acid, painted top and bottom with POR15, laid on fiberglas, more POR15. Dry. One more coat. Working great so far. Did the same on my battery box floor.

Tom
 
Fiberglass is great stuff and very strong when laid down with resin to bond it. I'm surprised that all you used was POR15 since it really is designed to bond to rusty metal. And fiberglass mat is designed to be used with a resin based bonding agent.

I used a chopped fiberglass in resin product called Tiger Hair to seal small pinholes. Then POR15 over the top when it cured. Almost invisible repair and sure beat installing new floors for a couple small pin holes. Using phosphoric acid first is a must to stop the existing surface rust.
 
Peter - I read some posts here about POR15 and fiberglas. Also found this on the POR15 website FAQ page:

CAN POR-15 BE USED WITH FIBERGLASS?
Absolutely. POR-15 is fully compatible with fiberglass and can be used to repair cracks in gelcoat. It will adhere better than polyester resin and has greater strength. Use also with fiberglass cloth to make super-strong surfaces in rusted-out areas. But be aware that POR-15 doesn't contain styrene and thus cannot melt fiberglass cloth like polyester resin does.

Tom
 
this is good news, I was planning on using this method to strengthen the floor pans on my brother's mgb, it has a couple of pinholes but is otherwise fairly rust free bodywise.
 
Phil - one trick I used ... put some masking tape on the underside of the floorpan to "block" the pinholes. That way, the POR15 won't drip through when you work the top of the floorpan. After the POR15 has dried, pull the tape off and coat the underside.

Tom
 
I purposely chose to do my frame at the end of the season. I wanted to give it ample time to just sit and cure after all of the hard stripping and cleaning.

I believe that if done properly from the bottom up, it's as good as any product, but it needs time to cure between applications and before driving on the road.
 
You guys have got me very excited about this POR 15 stuff. However, I am a little confused (a constant state!). I would like to copy what Tom has done on my boot floor. There are two or three pin holes that have rusted in the past. It also sounds as though POR 15 is just what I need for my wife's Morris Traveller floors that have surface rust on them. I was going to fibre-glass the TR boot floor and use Hammerite on the Morris floors.
I have just checked Frost's web site. They import all sorts of lovely car maintenance products from the USA. They seem to stock all sorts of POR 15 products - grey rust preventative paint, chassis painting kit, tie-coat primer, metal mask, etc, etc
What do I need? A good friend of mine said that he used POR rust encapsulator on his Healey floor, but I don't see anything like that listed.
/bcforum/images/%%GRAEMLIN_URL%%/confused.gif
 
Hi Nick.

Here's what you'll need:

https://www.por15.com/prodinfo.asp?grp=1&dept=1

You can find it at Frost and Holden (according to POR15's website anyway).

https://www.por15.com/International.asp

Tom
PS - what I didn't use last summer I put in the refrigerator. You never use it directly from the can; you pour what you need into another container and close the original can. It's still completely usable now, seven months later.
 
Thank you Tom and Paul. Frost have sold out of POR 15 but Holden have it in stock. It looks like great stuff and I think that I will remove the rust and paint, treat with phosphoric acid and then coat the area with POR 15.
Next question. Can you paint over POR 15 easily?
 
I never used the stuff and it sounds great, but I don't like what was done previously on my car. POR15 was used on the frame and I doubt the surface was properly prepared. A paint brush was used to try to cover up anything on the underside and prevent further rusting after being underwater. When I pulled the body off, I pressured washed the frame, including the POR15 areas. The POR15 can be removed with a pressudre washer in most places.

However, some bolts have the stuff in the threads, and they will break before caoming apart. Including two of the rear lug nuts. Before I knew it I had ruined two lugs and ripped them out of the axle. It appears a rear wheel was removed for "POR15ing" an area of the frame and a lot of POR15 spilled onto the lug. It must have been wet when the nut went back on, and now the two are inseperable.

So I guess it needs to applied properly.

Jer
 
POR-15 is tempramental stuff on the one hand and easy
to use and good stuff on the other.

I would suggest starting with only a pint. You won't
believe how far it will go until you begin to use it.
Kinda like the old oil-based paints that would spread
a long ways, only better.

POR is sensitive to air and moisture and begins to
cure/harden from its first exposure to same.

Go to Home Depot or other hardware store and buy a
couple of plain paint cans, 1 pint, with the lids.

When you open your first can of POR you might just find
it sealed so well that to open the can, you will destroy
it at or around the lid, so you'll want two cans,
one to transfer the amount you'll paint with (like about
1" to 2" of paint in the can bottom to start), and the
other new paint can to store the rest of the POR.

Do not shake the POR paint at any time. It can ill-affect
the end result. It is recommended the paint be transferred
from one can to the next by scooping out as opposed to
pouring....although I have poured and seemed to be okay,
but idea is not to mix air/air bubbles into the paint.

That said, if you are using POR-15 silver (it comes
in black as well) you will want to stir well with a
paint stick. It has some metal in the paint that collects
at the bottom and needs to be stirred in. Stir, then
transfer keeping what you'll use out and seal the
product holding-can with spare material immediately.

Have on hand a good supply of tight-fitting latex-type
gloves and WEAR THEM FROM THE TIME YOU BEGIN TO THE
TIME YOU FINISH! If an amount of POR gets on your
gloves, roll the glove off and place it directly into
a trash can and refresh the glove.

I do not recommend spraying POR because the fumes
are extremely toxic. Equipment can be compromised.

Buy a bunch of the very cheap foam brushes (bristles
will likely come out of a brush and end up in your
finish). Get a size foam brush that can be dipped into the opening of the 1 pint can. You will not attempt to clean and reuse any brush. Use them and place them directly into
a trash receptacle. If any brush gets too messy or
starts to fall apart, throw it away and get a new
one.

In terms of prep, clean with POR products named:

Marine Clean (to clean the surface pursuant to directions)
Metal Ready (to neutralize rust and add zinc phosphate
coating. (Thin white coat is okay to paint
over. Thick chalk? Scrape or brush off
to thin white coat and paint over with POR.)

POR-15 Silver: (To seal and neutralize rust) and when
applied with fiberglass, can repair rotted-out metal.)

POR-15 Black..okay, but color is harder to cover for
obvious reasons...real cool for frame stuff, but pretty
shiny and may not be so desirable. Can be over-coated
with any other POR product (like stuff with less shine)
but this should be the base-type coat to seal rust.

POR's generally go over one another in certain
ways and at certain times. For instance:
Once a POR product is applied, another can go over it
fairly soon....like once you can drag your finger
over the finish and it is dry enough not to transfer
to your touch, but still kind of tacky.

If a product were to dry too long, you'll have to
wait 24 hours, then sand the surface with sandpaper or
spray the surface with POR's primer coat paint after
the 24 hours. I forget the dry time on their new
primer, but it is pretty short. Old stuff took 24
hours.

Don't spill the stuff. Don't get it on you.
Just to clarify: Silver or black POR-15 are color
choices of products that do the same thing. You
do not NEED both, although, you could, if you wanted
to.

If you do get it where you don't want it, it can
be cleaned, if done immediately, with Acetone.
Do not use Acetone to thin.

POR vendors do sell a thinner...(usually not
necessary unless spraying, in my view), as well as
a paint stripper, which will remove the POR. Short
of that, dynamite might be an option...(just kidding.)
But it doesn't come off anything, anything once dry,
including your skin, easily. If it does get on you and dries, likely you'll have to let it wear off over days to
weeks, depending.

POR-15 black will likely turn a faded black color if
exposed to sunlight over time. Just something to
keep in mind. Other topcoats can go over that
will maintain their finish. Maybe one called
"Chassis Black,) maybe. I get mixed up, because they
have many products with similar properties. Be clear
on the ultimate finish you desire after applying
POR.

POR-15 Is a trade name. Typically, this name will
refer to the rust-blocker type of product. But,
they have a wide range of products that focus in
other areas such as gas tank sealers (I'm nervous
about this one) or paints for engines (slightly
different properties for this app, but not so much
rust stopper). I tell you this because someone might
say I painted with POR. But which product? Each
will be applied slightly differently with a different
purpose and a different finish.

Discuss with the vendor what you want to do and
take their lead.

Whew! Do I get long-winded or what? Sorry about that.
I just want you to understand the product and get
a very good result.

Best of everything to ya, and let us know how it
goes,
 
It's great stuff ... I used it on the MGB's floorpans, and I've used it with fibreglass on the floorpans in the TR6. I buy the sets of 6 small cans: then I don't have to mess around using another container and trying to re-seal the can, since one can is just about the right quantity for one coat, one job.
 
Just for the record. It took six of the small cans to do my TR6 underbody with two complete coats. And as you can see in the link above and below, we did everything, less the suspension, but including the floor pans.

I think that I still have a full six pack left, as I didn't believe that it would cover that well.

Get the Marine Clean and the Treatment and do it right. You won't be sorry.

https://www.74tr6.com/framestripping.htm
 
NutmegCT said:
2wrench - that is the best "POR15 handbook" that I've ever read. Great resource. Well done sir!

Tom
Click to expand...

Tom: Thanks. I worry; self conscious on wordy. Mean well.
 
Many years ago, I brush painted the front suspension, skid pan and several other pieces with POR 15. Several of the pieces were hung to dry from 2 x 4's strung between horses. Larger pieces I let dry on the boards.
The next day, when I lifted the pieces from the wood, I had large hunks of pine stuck to the parts.
POR 15 is very difficult to sandblast.
 
I've used POR and while I like the stuff, it's not the panacea that it's made out to be and it's not as easy to apply as their web site and literature make it out to be. On the previous page of posts it was said that POR was temperamental. An observation was also made that poor results may occur in cold rainy conditions. Both statements are true.

As with all paints and coatings, good results come with good prep work and it's important to follow the vendor's procedures. DO NOT cut corners. Plan on prep work taking a day (at least) and painting taking another day. Two coats are required and the application of the second coat is based not on elapsed time... but the tackiness of the first coat. Put the second coat on too early, you get solvent pop where pin-holes open up as solvent from the first coat tunnels its way through the second coat to get out. Apply the second coat too late... it won't stick well.

Tie Coat primer? Don't. Just don't. When the second coat reaches the same tacky condition used to determine when the first coat was cured enough to spray the second... spray a fog coat of the primer you'll use with your top coat... whatever it is. (Fog coat only). Allow 24 hours then apply a continuous coat of your regular primer and proceed as normal. Always allow a fairly long time for the POR to cure before applying a continuous coat of a NON - POR product. You want all the POR solvents gone.

IF you decide to spray, thin ONLY with the POR solvent. While you can clean uncured POR with regular lacquer thinner, you get terrible results if you use lacquer thinner to spray POR. I use cheap air brushes to spray POR (and I wear a respirator). Cheap air brushes are easy to take apart and clean before the POR sets.

When I buy POR I buy in the 6-pack assortment of pint cans. I buy 3 silver and 3 black. I use the silver as the base coat and the second coat is black. The contrasting colors makes it easy to know you've applied a complete and uniform coating. As stated above, POR is UV light sensitive so if the color of the exposed paint is important to you... plan on top coating it (see rant above about Tie Coat primer).

POR is a good, tough coating. They sell a starter kit that includes a pint of paint, small quantities of the prep chemicals, a foam brush and rubber gloves. It goes a long way and will give you experience with the product before you buy large quantities.

Regarding quantities, buy pints. The stuff has a relatively short shelf life and once opened it's even shorter. Moisture in the air accelerates the cure time. An open can won't stay fresh long. Also, stretch Saran or other plastic wrap over the entrance to the can before fitting the lid. This prevents the bonded on lid problem mentioned on the previous page. It's not a good idea to apply POR in cool damp conditions. You need warm moist air for quick and good results. Remember, the application of multiple coats is based on the tackiness of the coats as they cure... not a fixed length of time between applications.
 
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