[dataway]

I posted this in the Body Shop .. too late to delete it there, realized this is probably the place to post it.

Has anyone that has done the complex paint/masking work on a 68 grill tried using a liquid masking product. Thought maybe it might be an extra tool in the masking arsenal.

[Half-Inch Stud]

Sounds possible.

Honestly, I have repainted a few pairs of 68 Grills and don't recall the fuss being a time-consumer. Order of paint color mattered, and i don't recall masking. Think the technique i did was to free-spray and articulate the grill to control paint lay. think i sprayed the black from the backside.

Last step: May have used a mask (forget rag/cardboard/tape? ) to protect the finished grill zone while spraying the silver-gray front surround zones.

69 Bird (easier) and 68 LeMans (toughest is those little parts between the headlamps: find originals!) grills too.


Rally IIs needed the masking for sure.

[Greg Reid]

I did mine fairly recently and used about a quarter mile of masking tape. I had photos but I believe they were on my phone that I dropped in the lake (did I mention the phone was in my pants pocket at the time?)
I've never used any liquid masking for anything so I'm not really that familiar with it. Certainly sounds like a possibility.

[Shiny]

In my youthful working days I did some photolithography. We used both liquid and dry-film photoresists, both positive and negative (cures with and without light exposure). Point being, for something as tedious as a grill, you might find a liquid resist that allows you to use the part itself as the photo-mask.

I personally thing painting a liquid would be harder than cutting tape but my thinking is often tied to unnatural disasters...

What materials and what geometries are you considering?

[dataway]

I was thinking about a product like Peel-Tek, a latex based product. Thought maybe I could paint it on things like the back side of the GTO grill fins that should remain black. And the fin supports between the columns of fins. Areas that real clean lines are not necessary because they are not very visible.

Was thinking it might be less tedious for going around corners or masking small detail areas.

[Shiny]

There is also a world of thermal transfer materials that might be useful to mask (for example) the front edges of an eggcrate grill. The idea is to lay down a ribbon or film, then apply heat to the back side. The material sticks only where heated. In this case, it would stick only where there is contact to the front edges... The challenge would be to find a material that was easy to remove after painting. A liquid resist like you are asking about would dry to a "peelable" film. A thermal transfer film might need a selective solvent unless you could find a product specifically designed for paint masking.

[Greg Reid]

You probably know that it's not just the front edge that's argent, it's the front half. I don't know anything about liquid mask but it seems to me that it would be just about as tedious as tape masking if you have to paint the rear of each one of these segments.... Unless I'm just not understanding how it works.
I was trying to think of how to make a mask with something like poster board. Paint the entire grill flat black first, then cut the slits in exactly the right places and just slip it over the front of the grill. Spray the argent last.

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[dataway]

Yep it probably would be tedious to paint on, in general I'm more patient with a brush than with tape.
I've tried to think of a way to come up with a poster board mask. I could probably print up a grid that matches the grill on heavy printer paper and then cut it out with an X-acto.

I need to do a search to see just what widths are available for masking tape.

Despite all the pictures and info on the forum I'm still trying to wrap my head around just what gets painted and what doesn't.

So far I come up with ... for Grills, everything silver except the fin supports and the back half of the fines. For the Doors ... everything silver except the spaces between the fins.

[dataway]

Hey guys ... do a search on Amazon for "Narrow Masking Tape" .. I see they sell selections of 1/8, 1/4, 3/8, 1/2, 3/4 etc. Would have all those widths speed things up?

[Shiny]

Originally Posted by Greg Reid

You probably know that it's not just the front edge that's argent, it's the front half. I don't know anything about liquid mask but it seems to me that it would be just about as tedious as tape masking if you have to paint the rear of each one of these segments.... Unless I'm just not understanding how it works.
I was trying to think of how to make a mask with something like poster board. Paint the entire grill flat black first, then cut the slits in exactly the right places and just slip it over the front of the grill. Spray the argent last.

That looks like a big challenge and I understand why the liquid mask came up. How would the original manufacturer have masked this? Seems it would take a vacuum-formed plastic sheet or something similar. Maybe a latex mold material could be poured over the entire part, peeled off, then cut and put back in place? Yikes... good luck!

[Greg Reid]

I don't know how they did it but I've always suspected they had some type of template like I was thinking of with the poster board.
Dataway, you are right about what areas get what colors. I painted everything black first. As for the masking tape, yeah, I used regular low tack masking tape cut into strips the correct width. I applied them pulling them all the way across with the edges just touching the horizontal segments of the grills. The tape is only making solid contact with the vertical segments between the sections and it's simply suspended over the open areas. It is stiff enough to remain straight but I went through with a popsicle stick or whatever and made sure they were all straight against each horizontal segment. Then I laid the same width of tape on the horizontal vanes.
Let your originals be your guide as far as what remains black on the outer perimeter then tape that off.
Once all of that masking is done you can spray your argent.
As for tape, there is this-

[Greg Reid]

I meant to add that although l had the 3m tape at the time l did mine l decided to use regular blue masking tape and a steel straightedge to cut strips the exact width that l wanted. To me it's just a little easier to handle in tedious applications.

[roger1]

I feel your pain! My neck was sore for a few days after taping my grilles.
I just watched a few videos on the Peel-Tek site. For the price it's worth a shot to try but I have no idea whether it would work or save you any time if it did. Even if it doesn't work for your grilles, you might find other uses for it if the shelf life of the product isn't short.

[dataway]

Are the black areas of the grill just the native black plastic? Or are they painted at the factory?
Has anyone tried walnut shell blasting to remove the old paint?

[roger1]

I blasted my '69 grilles in my cabinet using Black Diamond media. It removes the paint and doesn't harm the plastic as long as I don't get too close with the gun.
Only the perimeters of '69 grilles were black and were native and not painted.

Here they are just out of the blasting cabinet and washed with soap and water:



You can see one spot where there was a crack and I ground it out and repaired with JB Weld.

[Half-Inch Stud]

Memory jogged: i definitely 1st sprayed black from the back, the gray into the grills from the front, then had to either mask some inside-front corners (or block the entire grill zone with a rag) when doing the last gray-spray from the front.

That final broad zone gray-spray is the deal maker.
Add Brite trim surrounds and be amazed.

Salient Points; the spray can quality and humidity matters,
articulating thr gril in 1-hand while thinking before pressing button in other hand.
Grill base surface texture ought be dead flat.
Oh! i recall blade-scraping the grill's leading louvers to get the right surface texture to remove the dings, and sharpen the edges: that was tedious, before Paint.
No primer used..adhesion was always high and reliable with the weather.
Outer zone BEYOND the brite trim metal was best left unpainted (texture!, risk of gloss!). Painted that outer zone once...once.

[dataway]

I think the 68's are quite a bit different than the 69 in the way they are finished .... Pontiac probably got tired of paying the vendor for whatever magic they were using to mask them

I was wondering if the black fin support columns, and the back of the fins were painted black, or were left the native black plastic. Just thought it would be surprising if they went to the trouble paint black plastic that was already black.

[dataway]

A tad off topic ... but one of my grills had two broken pins so I made a couple of replacements on the lathe out of nylon, tapped them for 10-24 and run a screw in from the bottom. Seem pretty sturdy, as sturdy as the originals anyway.

Going to throw some walnut shells in the blaster and see how it performs on painted plastic, sometimes those shells can surprise you and produce an almost virgin finish on things.

[J GLASGO]

How did the factory do this??

[Greg Reid]

Dataway, l'm pretty sure that the factory didn't bother with black paint. I just did it to freshen the appearance of the 50 year old plastic.