need some help with floor plan fix, peeling the coating, POR15, etc Options

[914 RZ-1]

The M/C leaked all over the floor plan. There's some rust as well. Before I put back everything I thought I would clean it all up.

1. What is the best way to get all the coating off the floor pan? It looks like some sort of asphalt/tar paper. It seems to be peeling off okay with a putty knife. I'm guessing I use some sort of solvent to get the remaining gunk off? Heat gun?

2. I have a kit that has cleaner/degreaser, metal prep and POR15. I also want to reseal around whatever that is (plug?) in the middle with some seam sealer. What order is this all applied?
-cleaner
-prep
-POR15
-seam sealer

OR
-cleaner
-prep
-seam sealer
-POR15

Or some other order?

3. I was going to leave the POR15 as the final coat, but do I need to paint over it? The car is silver/gray, the POR15 is gloss black. It's under the carpet and under the floor mat, so it will not show. I'm more concerned with keeping the rust at bay.

4. Where should I stop the painting? At a seal? At one of the changes in contour of the floor pan? Please note that the car was in an accident many years ago (before my ownership) and was repaired, but the floor pan is still a little uneven. My concern is that the paint will wick under the tar paper, but is that even an issue?

Here's a photo, since I know we all like pictures. There is a pile of tar paper on the left:


Thanks!
-Jeff
------------

[bkrantz]

How much rust? And how far do you want to go?

If any more than surface rust, then the "right" way to repair to to cut and replace all rotted metal. If surface rust, you can make an adequate repair with rust treatment.

To remove the factory tar sheet, people use all kind of methods. A popular way to to apply some kind of deep freeze to make it more brittle and easier to chip off. Otherwise just use hand labor.

[ogdougy]

If you want to remove it with that "deep freeze" method.

mix dry ice and a high percentage isopropyl alcohol (even better if you have methanol) in a bin and lit it sit a little bit then pour over the tar paper. It will chip off really easily.

Same concoction is great for press fit parts.

[technicalninja]

I'd do it the first way.

The POR 15 needs to be directly on the metal.

POR 15 turns an ugly purple if exposed to UV rays. Where you are hitting doesn't matter.

NOTHING will stick to POR15 without the dried surface being prepped with sandpaper.

Normal sandpaper will not touch it! It is EXTREMELY hard to scuff up.

POR15 has a "tie coat" primer that does actually work pretty well but it needs to be applied after the POR15 has "tacked" off but before it has hardened.

POR15 is just high-quality paint that has a serious dose of isocyanates in it.
This is "super glue".
The fumes from this will mess you up and in high doses might put you in the ER.

I once did the floor pans in a Z car and even though I had airflow I thought I was going to die.

POR15 is dangerous to work with in an enclosed space.
BIG fans. lots of airflow, and outside is SOP with me now...

You do not want to POR15 anything you are going to weld.
Removing hardened POR15 requires a grinder. Soda or sand blasting doesn't work.
Paint stripper doesn't work.
It's the most permanent paint I've ever used.
It's harder to remove than powder coating...

POR15 sells fiberglass velum cloth, This is fiberglass mat that is so thin you can see through it. It can be used to patch small holes and if done right it doesn't look like a patch. It's rock hard and you can drill accurate holes in it if you need to.

[Superhawk996]

POR15 sells fiberglass velum cloth, This is fiberglass mat that is so thin you can see through it. It can be used to patch small holes and if done right it doesn't look like a patch. It's rock hard and you can drill accurate holes in it if you need to.

Please don’t encourage the use of fiberglass to fix floor pans. The 914 restoration community has seen plenty of that DAPO fix. (IMG:style_emoticons/default/av-943.gif)

[technicalninja]

Please don’t encourage the use of fiberglass to fix floor pans. The 914 restoration community has seen plenty of that DAPO fix. (IMG:style_emoticons/default/av-943.gif)

I didn't.
Reading comprehension issues?

POR15 can be used with the velum to repair minor holes, not major reconstruction.
It can be used to stop corrosion temporarily and often ends up a permanent fix if the user never gets to the point of welding new material on.

The holes I've fixed using this method you would not be able to find, you wouldn't be able to see the patch, and it will NEVER corrode there again.
I have not seen a failure of a POR15 patched hole in my life...

I also stated you DO NOT want to POR15 anything you are going to weld.
The stuff is a nightmare to remove once it's cured.
If you let it cure on your skin you have to wear it off. Nothing removes it.

[Superhawk996]

Please don’t encourage the use of fiberglass to fix floor pans. The 914 restoration community has seen plenty of that DAPO fix. (IMG:style_emoticons/default/av-943.gif)

I didn't.
Reading comprehension issues?

Chill dude - it was a joke complete with picture of American philosophy of if a little is good more is better.

[technicalninja]

Chill dude - it was a joke complete with picture of American philosophy of if a little is good more is better.

You have an interesting way of joking...

It came off as:

"Please don’t encourage the use of fiberglass to fix floor pans."

I don't like using bondo-fiberglass in bodywork.
I prefer lead...

I would never suggest fiberglass for any metal work.

When I first saw others using POR15 to fix small holes I was a dis-believer.
Until I tried it myself...

It is the ONLY small hole patching material I've ever seen actually work in a permanent fashion.

I thought the fiberglass velum would print through it and you could see it.
Nope, not at all. The POR15 is thick enough and the fiberglass is thin enough that it just blends in.

It can work for small pinholes in a basically good panel.
It cannot fix major destruction.

[914 RZ-1]

Thanks for the help!

I was able to find more threads on tar board removal, especially since I was searching for "tar paper "and "floor board" and not "tar board".

Seam sealer will go on AFTER POR15.

This is all surface rust, so no floor pan removal.

I plan on wearing a respirator and having a fan on and the garage door open. The car is on jackstands, so moving it out is not an option. I will scuff the surface for paint. What paint? I just need something to cover it. I was thinking gray paint that I could brush on. Thoughts?

Can anyone answer my last question: Where should I stop the painting? At a seal? At one of the changes in contour of the floor pan? Please note that the car was in an accident many years ago (before my ownership) and was repaired, but the floor pan is still a little uneven. My concern is that the paint will wick under the tar paper, but is that even an issue?

I'm thinking I can use seam sealer where the tar board ends. Seems the paint is basically glue, so maybe if it does wick under the tar board, it will harden anyway.

[Superhawk996]

In my opinion, you’re over thinking it.

It’s all under carpet. No one sees it.

Don’t sweat a little paint or POR wicking into a sheet metal seam or under the tar. The tar sucks and is basically a place where rust begins to grow under it. No matter what you do short of removing it all, it’s not going to look pretty.

As far as paint, you could leave as just POR (no UV exposure). If you want to paint over POR, it gets trickier - spray paint mist will drift and get on carpet and interior. For a quick fix, you would be better off using a brush. At that point I come back to just leave the POR.

What type of paint? 2k epoxy/urethane would be great but it’s pricy. A decent single stage enamel over the POR and/or seam sealer would be fine. Find what you can at FLAPS or get a pint of paint mixed from local PPG distributor if you want to try to color match. But again no one sees it under carpet.

[Superhawk996]

Good job trying to do this well. It’s always a complete fiasco when the master cylinder leaks in that area.

[914werke]

You have an interesting way of joking... It came off as: "Please don’t encourage the use of fiberglass to fix floor pans."
I don't like using bondo-fiberglass in bodywork. I prefer lead...
I would never suggest fiberglass for any metal work.
When I first saw others using POR15 to fix small holes I was a dis-believer.
Until I tried it myself... It is the ONLY small hole patching material I've ever seen actually work in a permanent fashion.

But it does appear you are promoting the use of POR-15 which many would argue is a crap product with no good/useful application.
LEAD, was replaced by plastic for good reason & is generally no longer used (except in small specific handcraft resto circles)
There is a better METAL solution to fixing the pinholes in areas that are determined to be solid enough to keep, its called BRAZING (IMG:style_emoticons/default/rolleyes.gif)

[technicalninja]

The tie-coat primer that POR15 sells is grey.

At least it was grey...

I just checked and the "tie coat" is gone and has been replaced by their "High Build" primer that the description reads "Tie coat" and this stuff can be sprayed on CURED! POR 15.

If this works, it is an improvement.

I could not determine what color it is now...

Like all of the POR15 products it's on the more expensive side of paint supplies.
Today a qt is $42 before shipping.

POR15 is a messy job. I put on clothing and shoes that I don't car about. A hair net can save your ass. All of the items that touch the paint should be considered single use ONLY!
Lots of cardboard under what you are doing. This crap will get everywhere and if you get it off your skin in 15 seconds you can emerge un-stained but that seldom happens when I have used it.

Be super careful about not getting any paint at all in the grooves at the top of the can where the lids fit. A tiny dot will make the lids impossible to remove the next time you want to use it. Buying it in the little 4 oz cans will reduce lost paint but it's expensive this way.
I buy it in quarts and after it has been opened the first time I transfer it into glass jars that I snag from my wife. Prego sauce jars work great.
Once again DO NOT get any on the edges where the lid fits on the jar.
I use a super tiny amount of silicone grease around the glass edge to help removal down the road.

Store it in a cool/dry/dark place. The inside of a refrigerator is an excellent choice.

If you cannot get the lid off down the road just poke a couple of holes in it and pour it into a new glass jar. I always have a replacement jar ready if I'm going to open an old one.

The instructions say you can double coat it...

For me, the second coat goes on like shit and looks like shit when it dries.
I do one heavy coat. You will be able to see brush strokes in it but this stuff "flows" for quite a while and the cured product does not show the brush strokes.

A little goes a long way. I'm commonly just using 1-2 ounces on small projects.

I use cheap ass "chip" brushes from Harbor freight and am not trying to clean them at all.

I'd really like to try this stuff through an air brush, but my current air brush is far to expensive to throw away after a single use and I've been hesitant to try.

POR15 solvent works great on the paint component but doesn't seem to clear the isocyanate component. I've never been able to save any tool that touched POR15.

Do NOT put paint back in the can after it's come out. It will set the entire can off.

I have successfully stored POR15 in my shop refrigerator for 6 years plus doing the above-mentioned tips.

If you screw up and get some in your hair DO NOT try to clean it out. Let it dry and cut it out. I know this from personal experience.

When fresh out of the can it's runny and will get everywhere, it will seep under everything and will seal crap you might not want it to. Fine line masking tape (the expensive stuff you buy and an Automotive paint store) can be used to mask areas you do not want it but expect some bleed through.

Dried on your skin it will last 4 weeks until the skin come off. Dried on a concrete garage floor it will last 2 years.
On cloth it's permanent.

It's nearly impossible to get off but the one thing I haven't tried is fire itself...

I think a torch would take this stuff off, but I wouldn't want to be anywhere near the resultant smoke.

Hope this helps!
POR15 is a good product but it has many application drawbacks.

[technicalninja]

But it does appear you are promoting the use of POR-15 which many would argue is a crap product with no good/useful application.
LEAD, was replaced by plastic for good reason & is generally no longer used (except in small specific handcraft resto circles)
There is a better METAL solution to fixing the pinholes in areas that are determined to be solid enough to keep, its called BRAZING (IMG:style_emoticons/default/rolleyes.gif)

Those who have failed with POR15 didn't use it properly.

My Dad has been building fiberglass parts for years. I have a bunch of experience in the use of a variety of filling chemicals,

I'm not even sure you can do lead work any longer. I haven't done any in a couple of decades.

Every single use of a plastic filler on a steel bodied car will shrink with age. Somewhere down the road, you will see it "print" out beneath your paint.
If you have a garage queen that never sees sunlight it might take a real long time.
Out is the sun every day, the repair will show back up more quickly.

I agree with you regarding brazing over POR15. Brazing requires a much cleaner surface/parts to work properly and a user really needs a bit of experience before trying to braze holes in a 50-year-old floor pan.

Brazing is the second-best way to fix pin holes right after tig/mig and a brand-new panel.

POR15 can be used by a DIY guy easier than brazing.
Brazing is far better however.
Brazing is cheaper in the long run as well.

[SirAndy]

Those who have failed with POR15 didn't use it properly.

I disagree. I've seen too many failures, my very own included.

I won't use POR-15 on anything anymore and neither should the OP.
(IMG:style_emoticons/default/shades.gif)

[technicalninja]

I'm all ears for other's opinions.
Please expand on how/why it didn't work for you.
New data always shapes my perception.

You are directly against it.
I value your insight.
Please tell me why you didn't like it.

[Superhawk996]

I'm not even sure you can do lead work any longer. I haven't done any in a couple of decades.

Lead is still alive and well. There are also lead free, tin based alternatives now.

Lead is also a viable filler over pitted metal but as with brazing, MIG, TIG or anything else the real problem is getting the rust out of the bottom of the pits. Phosphoric acid / Ospho is really the only way I’ve had any success. Even then, I find that it usually requires a couple rounds of Ospho and the wire wheel to dig it out of the pits. Never fun.

Bottom line for 914s . . . The small holes or pitting you see are just the tip of the iceberg. Better off to cut out and replace with good metal. But of course that isn’t as easily done as we wish it might be.

Small pinholes - exterior as seen - tip of the iceberg


The rest of the iceberg that you can’t see

[technicalninja]

POR15 has an expensive metal prep called Metal-Ready.

It is phosphoric acid based.
Their website makes it sound totally safe.
"This metal-etching rust neutralizer is not caustic, corrosive, toxic or flammable."
What they didn't say was not acidic...

The first use of phosphoric acid for me was a early Alfa spider that my father did a multi-color paint job on. I was 12 years old and helping him prep the bare metal car.
We used Dura-Etch which was phosphoric acid based.
It was dirt cheap at the paint shop so POR15s Metal-Ready is an expensive re-use of a old product.

What I learned from that Alfa is to never ever lean on a windshield as I broke the one in that car...

[Superhawk996]

POR15 has an expensive metal prep called Metal-Ready.

I’ve used Metal Ready too. It has zinc in it in addition to the phosphoric acid. Ospho is phosphoric acid without the zinc.

Used properly, Metal Ready holds off atmospheric humidity and yellow flash rust pretty well. Ospho will hold off rust but only by leaving it to dry in the panel. Then you need to go back and re-wet with Ospho, remove excess, neutralize, dry and paint before flash rust occurs.

Different tools for different jobs but there are times I prefer the Metal Ready.

[914 RZ-1]

The tie-coat primer that POR15 sells is grey.

At least it was grey...

I just checked and the "tie coat" is gone and has been replaced by their "High Build" primer that the description reads "Tie coat" and this stuff can be sprayed on CURED! POR 15.

If this works, it is an improvement.

I could not determine what color it is now...

Like all of the POR15 products it's on the more expensive side of paint supplies.
Today a qt is $42 before shipping.

POR15 is a messy job. I put on clothing and shoes that I don't car about. A hair net can save your ass. All of the items that touch the paint should be considered single use ONLY!
Lots of cardboard under what you are doing. This crap will get everywhere and if you get it off your skin in 15 seconds you can emerge un-stained but that seldom happens when I have used it.

Be super careful about not getting any paint at all in the grooves at the top of the can where the lids fit. A tiny dot will make the lids impossible to remove the next time you want to use it. Buying it in the little 4 oz cans will reduce lost paint but it's expensive this way.
I buy it in quarts and after it has been opened the first time I transfer it into glass jars that I snag from my wife. Prego sauce jars work great.
Once again DO NOT get any on the edges where the lid fits on the jar.
I use a super tiny amount of silicone grease around the glass edge to help removal down the road.

Store it in a cool/dry/dark place. The inside of a refrigerator is an excellent choice.

If you cannot get the lid off down the road just poke a couple of holes in it and pour it into a new glass jar. I always have a replacement jar ready if I'm going to open an old one.

The instructions say you can double coat it...

For me, the second coat goes on like shit and looks like shit when it dries.
I do one heavy coat. You will be able to see brush strokes in it but this stuff "flows" for quite a while and the cured product does not show the brush strokes.

A little goes a long way. I'm commonly just using 1-2 ounces on small projects.

I use cheap ass "chip" brushes from Harbor freight and am not trying to clean them at all.

I'd really like to try this stuff through an air brush, but my current air brush is far to expensive to throw away after a single use and I've been hesitant to try.

POR15 solvent works great on the paint component but doesn't seem to clear the isocyanate component. I've never been able to save any tool that touched POR15.

Do NOT put paint back in the can after it's come out. It will set the entire can off.

I have successfully stored POR15 in my shop refrigerator for 6 years plus doing the above-mentioned tips.

If you screw up and get some in your hair DO NOT try to clean it out. Let it dry and cut it out. I know this from personal experience.

When fresh out of the can it's runny and will get everywhere, it will seep under everything and will seal crap you might not want it to. Fine line masking tape (the expensive stuff you buy and an Automotive paint store) can be used to mask areas you do not want it but expect some bleed through.

Dried on your skin it will last 4 weeks until the skin come off. Dried on a concrete garage floor it will last 2 years.
On cloth it's permanent.

It's nearly impossible to get off but the one thing I haven't tried is fire itself...

I think a torch would take this stuff off, but I wouldn't want to be anywhere near the resultant smoke.

Hope this helps!
POR15 is a good product but it has many application drawbacks.

It does, thanks. I painted my car myself, so I'm familiar with using catalyzed paint and what a PITA it can be to clean up.

I'm wearing throw-away clothes (hair tied back, safety glasses, etc) and using throw-away brushes and rags. The paint will be chucked as well, since I've never had good luck storing anything like this. I bought a small, 4 oz can for this very reason.

I still have some good tape left over, so I will be using that. Thanks for the heads-up about bleeding and getting paint in the rim, clean up, etc. This is the kind of useful info I needed.