New front pan - how to finish paint / POR

mvanbens · 05-21-2007, 01:04 PM

Long time lurker and archive searcher. I have not posted much but thought I could get some advise on this one. I have replaced the front pan on my 70T / RSR look with parts from Stoddard. Good old Restoration Design would not return calls.

I'm at the point of being done with welding and ready to start finishing the new metal. The pan came with some type of rust preventive coating that I removed from all welding areas. Same for the upper support that attaches above the torsion bar front mounts. So now I have a mix of rusted metal, bare metal, primed metal and the original undercoating coated metal.

Please provide suggestions for finishing this thing off. I have POR15 and Wurth undercoating ready to go. My primary concern is to prevent future rust. My secondary concern is appearance and to conceal the new panel from the casual eye so that it does not look like it was replaced. I would also like to avoid having rubber / sticky undercoating in the trunk area.

I have powdercoated my tank black and now just need to have the POR tank liner kit installed which I already have. I plan on going to a single battery in the smugglers box and have been contemplating cutting-out the original battery boxes. Any pros or cons to getting rid of the original battery boxes. This car is far from original so I do not think it will impact value.

Thank you. - Matt

sballard · 05-22-2007, 04:45 AM

mvanbens-

Nice to see your work. I am also replacing my front pan, but I am a little behind you in progress. I am still cutting out the old one, but I have similar questions. I also plan to use POR-15 and the Wurth stoneguard. Did you have to fabricate new longitudinal sections?

Steve

berettafan · 05-22-2007, 05:10 AM

question (in my best Dwight Shrute voice):

-does your gas tank have the plastic whirl pot in it?

thanks-

Erik

Porsche_monkey · 05-22-2007, 05:48 AM

I had poor results putting stonegaurd over POR on fresh metal. I would use a self-etching primer, rather than POR, if I had to do it over.

scottb · 07:18 AM

Do a search for "darryld." He recently did a full restoration, including a pan replacement, and he documented the process extremely well. I'm sure he'll have suggestions for painting. He did a full thread on how he matched the texture of the undercoating -- he spent hours dabbing with his finger!

As to POR-15, my understanding is that it is not a primer and should not be used, alone, on bare metal. Rather, they sell a product called "Metal Ready" which should be used on bare metal before using POR-15.

From the company's website:

WHAT IS THE BEST SURFACE ON WHICH TO PAINT POR-15?
POR-15 likes rusted surfaces best. Seasoned metal and sandblasted metal are also good. POR-15 does not adhere well to smooth, shiny surfaces, but will adhere well to those surfaces with the proper preparation.

Scott

berettafan · 05-22-2007, 07:17 AM

and make a point of thanking him for his contribution. he recently lost his wife and i would think any positives in his life would be well appreciated right now.

mvanbens · 05-22-2007, 09:28 AM

sballard - Did you have to fabricate new longitudinal sections?

I had to add some material at the ends of the longitudinal sections. I was able to use some of the cut-off from the new front pan and some extra material I had around the garage. I also needed to add material where the pan meets the front lateral support. I added a few pictures to showing this.

berettafan - does your gas tank have the plastic whirl pot in it?

I really hope you are joking. I have not been able to get that good of a look into the tank but I imagine if it did have a whirl pot it doesn't now. The powder coater made no mention of plastic dripping-out during the bake process.

scottb - I will do a search for that thread. I can tell you that I will not spend time dabbing with finger to get a perfect match. I do have the metal ready for application before POR.

-Thanks Matt

sballard · 05-22-2007, 12:55 PM

Thanks mvanbens. Your rust patterm looks very similar to mine. It seems that almost all the rust formed under the tank support crossmember. Must be a terrible moisture trap there. I wonder if it would help to apply extra rust protection there such as a cold zinc treatment or maybe drill a couple more drainage holes in the pan.

Steve B.

mvanbens · 05-23-2007, 11:51 AM

Steve B,
I would agree that under the tank support cross member is a terrible moisture trap. The rust may be a problem there because it's hard to get in there and rust proof after it has been welded together. How about temporarily blocking the drain holes and then doing the entire POR process draining and drying with compressed air between each step. I actually contemplated this last night.

I figured I could drain the POR-15 from the holes and still re-use on other surfaces. This does sound like a lot of work though.

I think I'm going to leave the battery boxes. They are in decent shape and it's just more work to remove them and weld-in block-off plates.

-Matt

DanielDudley · 05-23-2007, 05:16 PM

After using POR 15, there is a POR product called Tie Coat, that acts as a bonding primer over POR 15. It sticks to the 15 without having to prep, and provides a surface with tooth for the next coat of whatever.

Jeff Hail · 05:46 PM

Grind and smooth all plug and seam welds. Sand or blast all surfaces that have been replaced and adjacent original metal. Spray with epoxy primer first. The key is to start with good adhesion and eliminate all exposure to air or moisture.

By the way nice welds!

azasadny · azasadny's Garage

Matt,
Where are you located? I'm in Wyandotte...

mvanbens · 05-24-2007, 09:01 AM

Jeff,
Thanks for the compliment on the welds. I must have put out about dozen undercoating fires behind the front panel while installing the new pan. Whatever the coating is that was on the pan to prevent rust does not like heat.

Art,
I'm in Walled Lake.

I hope to do the POR-15 treatment tonight. I have a few old sheets that will save the garage floor. I will snap some pictures when done.

Anybody ever use the seam sealer sold by POR? I bought some with plans to seal the panel joints after the POR treatment. It's brushes on and looks to be very thick. Any words of wisdom?

azasadny · azasadny's Garage

Matt,
I work in Novi, let me know if you need a hand and I'll try to make plans to be there...

Porsche_monkey · 05-24-2007, 09:04 AM

You can get good seam sealer from any automotive paint shop. I doubt POR's product is worth the extra money they will charge.

coldstart · 05-24-2007, 09:11 AM

Nice looking job. If you want, I have leftover POR-15 Metal Ready from my front pan job (I just ground it down to bare metal and repainted it.)

mvanbens · 05-25-2007, 11:52 AM

azasadny,
Thanks for the offer. I may take you up on it next time.

Well last night was late. I removed all the primer and prepped the surfaces with the aggressive scotch brite pads on die-grinder. I then applied marine clean, rinsed with warm water and dried. I then applied metal ready, rinsed with warm water and then fully dried (took about an hour of compressed air and heat gun work). Then I applied the POR-15. I did two coats about an hour between. This was not the recommended amount of time between coats but I refused to stay up to 3am to apply the second coat.

What a messy job this all was. I must have mopped the floor about twenty times to catch all the runoff. Despite my best efforts for protection the POR-15 still got on my arms and a finger or two. I used an old comforter to catch the dripping POR-15.

This morning I put on the Eastwood seam sealer. My next step is to apply the Wurth undercoating.

-Matt

sballard · 05-25-2007, 12:47 PM

Matt-

Looking good! I can't wait to get to that stage. I hadn't thought about the seam sealer which is obviously a good idea.

Steve B.

berettafan · 06-05-2007, 05:49 AM

any updates?

mvanbens · 06-05-2007, 07:10 AM

Sorry to be slow on the updates. I have since applied the WURTH undercoating. It looks good but certainly does not match the original undercoating texture. I will post some pictures of the finished product soon.

-WARNING-
Do not make the same mistake I made. I forgot all about the little bracket that locates the bottom of the washer fluid reservoir. I never ordered this bracket but was able to get the old one separated from the take-out pan. I'm not sure what I'm going to do yet to attach the bracket. It would have been best to weld it to the pan before all the POR, seam sealer, and Wurth coatings.

-Matt