# Some questions about exterior painting



## ProWallGuy (Apr 7, 2007)

I usually don't touch exterior work, but this is for a real good customer of mine, and its a small job, so I want to do it just to get outside for a bit.

Its been a minute since I've tackled exterior work, so I have a couple questions regarding prep of some areas. Hoping some new products have come out that might address these issues easier than when I last ran into them. 

The first issue is that metal bar (don't know the name of it, care to enlighten me?) you see that runs across the top of a garage door. They always rust. How would you exterior guys prep/prime/paint this?


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## ProWallGuy (Apr 7, 2007)

Second issue is the bottom of some metal-clad columns. The base of one is bubbling/peeling. It appears to be galvanized metal. How would you prep/prime/paint this? TIA


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## DeanV (Apr 18, 2007)

For the metal strip above the garage door, that will usually bleed back through with time, but we tend to sand, rust converter, and Benjamin Moore Metal and Wood enamel (oil). I would match to the brick, not the white, so when it starts bleeding through again it will not looks as obvious as if you painted it white.

For the pillar bases, I have never seen metal ones before, but I think a good sanding to removed the white oxidation and hit with a latex metal and wood enamel would be fine. Almost any latex product should stick fine to galvanized metal, just do not use oil.

If it was new galvanized, it should be solvent wiped as well or some kind of etching prep (galvaprep is one brand) but given the age and condition, I do not think that is needed in this situation.


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## Bender (Aug 10, 2008)

What Dean said.
They're both going to be almost impossible to stop the rust because they will always be exposed to more water.
The metal is called a lintel.


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## jacob33 (Jun 2, 2009)

I have had good luck priming the metal bar with penatrol and than an oil paint. Obviously sand and prep like suggested previously.


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## 4ThGeneration (Apr 17, 2007)

I imagine that the rest of the metal under the non arched windows need some attention as well. We would steel wool the metal, dust and apply ospho. after that dries we would apply a exterior oil based product in black.



As far as the metal columns. The best scenario is to be the first one to paint them, but we would always wipe down galvinized metal with mineral spirits. Then we followed up with painting them with a 100% Acrylic latex coating. I have seen other contractors paint their galvi metal using an oil based, but the homeowners usually did not like that when the paint started peeling in strips for some reason :thumbup:

Whatever you do, do not use steel wool to sand down the peeling paint because once you repaint it using latex it will rust through if you do not get rid of all the steel wool particles.


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## mustangmike3789 (Jun 11, 2011)

Its obvious that I probably don't know anything preventing corrosion or paint failures on those types of metals so maybe I shouldn't give any advice on this topic at this time. Don't want to offend anyone with my lack of knowledge and overkill on surface prep and product suggestions. Most of my experience is only in harsh marine environments and probably wouldn't help in this situation anyways.


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## DeanV (Apr 18, 2007)

This may be a situation where industrial methods may help since typical residential methods only score acceptable in the rust prevention category.

I still stand by the typical aluminum siding paint job not being a difficult situation in the least. I do not think I have ever even seen an aluminum siding paint job fail regardless of who painted it. My comment in the siding thread was not directed at you in particular, btw.


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## Sully (May 25, 2011)

http://mabpaints.com/products/products.asp?id=278

Check out the rust-O-lastic. That stuff is the bees knees when it comes to rusty metal. I would use a converter or hydro prime after wire brushing and sanding that rust away. If you talk to your Sherwin Rep I bet they can special order you a gallon of that stuff since they bought out MAB a few years ago. Make sure you get some one who knows what there doing or if you'd like I'll give you a number to a philly store and I bet you can have then ship it down to you. That may be a little farfetched but it is really durable stuff I tell ya.:yes:


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## NACE (May 16, 2008)

Oil based paint, alkyds, create supponification on galvanized metal. A zinc soap is the result of alkyds, acid and alcohol reacting with zinc. Either a phenolic alkyd, water based, or epoxy should always be used on galvanized. A water based DTM is prefered or a latex metal primer and latex topcoat. Ever see stop lights peeling like a snake? They were sprayed with a standard alkyd and fail within six months. All new galvanized must be cleaned first with a solvent wipe to remove surface oils used in the galvanization process. Acetone, simple green or any degreaser for blood fat oil and grease fine.


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## Lambrecht (Feb 8, 2010)

NACE said:


> Oil based paint, alkyds, create supponification on galvanized metal. A zinc soap is the result of alkyds, acid and alcohol reacting with zinc. Either a phenolic alkyd, water based, or epoxy should always be used on galvanized. A water based DTM is prefered or a latex metal primer and latex topcoat. Ever see stop lights peeling like a snake? They were sprayed with a standard alkyd and fail within six months. All new galvanized must be cleaned first with a solvent wipe to remove surface oils used in the galvanization process. Acetone, simple green or any degreaser for blood fat oil and grease fine.


Can you give an example of a phenolic alkyd?


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## Ultimate (Mar 20, 2011)

If it were me: For the lintels:

Sand well then wipe w laquer or mek to clean
The must for rust then 
Kem Kromic then
Zinnser then 
topcoat w acrylic.


Rust is an issue on the coast. Aluminum siding doesn't even live a long life here.


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## Ultimate (Mar 20, 2011)

Almost identical process on this. Well, the must for rust, kem kromic and zinnser is the same. This was a strip, scrape and strip some more first with different topcoating.


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## Mike's QP (Jun 12, 2008)

Wire wheel and hand tool clean, sp1, oil prime and latex top coat, on new galvanized we vinegar wash, degreases/ slight etch (acetic acid) but on old stuff sand,sp1,paint


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## Ultimate (Mar 20, 2011)

What is sp1?


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## mustangmike3789 (Jun 11, 2011)

FatherandSonPainting said:


> What is sp1?


Sspc-sp1 is solvent cleaning.


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## mustangmike3789 (Jun 11, 2011)

im not a big fan of "rust converters" just because i do not have a lot of knowledge or test results proving them to be effective. as far as i know, rust converters have tannic acis or phosphoric acid blended with a resin,(tannic acids being the better choice). the acid reacts with the iron oxide which converts it to a "primeable" substraight. this does not mean that it effectively stops rust. i feel that penetrol would be a cheaper/better option. penetrol is a mix of penetrating oils mixed with a resin to block oxygen and moisture contact with metal that can be mixed with paint or directly applied to rusted metal before painting. oil based paint with penetrol would be a good choice to apply to the properly prepared steel or a direct to metal epoxy used to block oxygen and moisture from the corrosion cell. a zinc primer applied directly to the properly prepared steel with an epoxy midcoat and urethane top coat would be better unless you can afford to metalize:blink:. now,,,as far as the extruded aluminum columns and the alloy mix aluminum bases with the baked on enamel coating that almost always fails due to a lot of abuse and direct contact with concrete and cleaning agents... these bases should be cleaned to bare metal, washed, and solvent cleaned with a non-hydrocarbon solvent, etching primer and top coated with a good dtm acrylic or appropriate epoxy/urethane finish. this may sound a little extreme but bare aluminum is different than tightly adhered coated aluminum. as far as i know products made from aluminum such as pipes, airplane skins, boats,traffic lights and aluminum siding are made from aluminum, and these bare aluminum products should be properly prepared and primed with an etching primer or anodized(electroylic passivation) finish before coating unless the use of a baked on phenolic coating is being used. any breach(scratch/pinhole) in a protective coating system that allows moisture/oxygen to oxidize the substraight that expands the metal, weather it is iron oxide or aluminum oxide (passivation) will cause failures such as improperly coated aluminum traffic lights that are peeling. i have reason for my long winded descriptive madness but thats is another story.:whistling2:


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## TJ Paint (Jun 18, 2009)

mustangmike3789 said:


> i have reason for my long winded descriptive madness but that is another story.:whistling2:


What about the finishes that are designed to coat over sound areas with rust on them? PPG has some industrials designed in this fashion.


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## chrisn (Jul 15, 2007)

Hey,Tim, you get enough info yet??:blink::laughing:


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## mustangmike3789 (Jun 11, 2011)

TJ Paint said:


> What about the finishes that are designed to coat over sound areas with rust on them? PPG has some industrials designed in this fashion.


those would fall under the oil base or dtm epoxy mentioned above.


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## NACE (May 16, 2008)

Lambrecht said:


> Can you give an example of a phenolic alkyd?


Some universal oil base primers, mostly for corrosion control and industrial applications, some dry falls, uni- bond for example, epoxy esters and aerosols. Rapid drying enamels


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## Ultimate (Mar 20, 2011)

mustangmike3789 said:


> im not a big fan of "rust converters" just because i do not have a lot of knowledge or test results proving them to be effective. as far as i know, rust converters have tannic acis or phosphoric acid blended with a resin,(tannic acids being the better choice). the acid reacts with the iron oxide which converts it to a "primeable" substraight. this does not mean that it effectively stops rust. i feel that penetrol would be a cheaper/better option. penetrol is a mix of penetrating oils mixed with a resin to block oxygen and moisture contact with metal that can be mixed with paint or directly applied to rusted metal before painting. oil based paint with penetrol would be a good choice to apply to the properly prepared steel or a direct to metal epoxy used to block oxygen and moisture from the corrosion cell. a zinc primer applied directly to the properly prepared steel with an epoxy midcoat and urethane top coat would be better unless you can afford to metalize:blink:. now,,,as far as the extruded aluminum columns and the alloy mix aluminum bases with the baked on enamel coating that almost always fails due to a lot of abuse and direct contact with concrete and cleaning agents... these bases should be cleaned to bare metal, washed, and solvent cleaned with a non-hydrocarbon solvent, etching primer and top coated with a good dtm acrylic or appropriate epoxy/urethane finish. this may sound a little extreme but bare aluminum is different than tightly adhered coated aluminum. as far as i know products made from aluminum such as pipes, airplane skins, boats,traffic lights and aluminum siding are made from aluminum, and these bare aluminum products should be properly prepared and primed with an etching primer or anodized(electroylic passivation) finish before coating unless the use of a baked on phenolic coating is being used. any breach(scratch/pinhole) in a protective coating system that allows moisture/oxygen to oxidize the substraight that expands the metal, weather it is iron oxide or aluminum oxide (passivation) will cause failures such as improperly coated aluminum traffic lights that are peeling. i have reason for my long winded descriptive madness but thats is another story.:whistling2:


I will look into this process and maybe try it out. There is a safe I am painting after that doorway is complete. Ancient. RUSTED is an understatement. Pics to come.


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## 4ThGeneration (Apr 17, 2007)

FatherandSonPainting said:


> I will look into this process and maybe try it out. There is a safe I am painting after that doorway is complete. Ancient. RUSTED is an understatement. Pics to come.


If you ha\ve access to safes you may be in the wrong line of work!!!

:ninja:


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## Ultimate (Mar 20, 2011)

The client is hoping to be able to get someone to open it. 

The door has two applications of The Must for Rust and two coats of Kem Kromic.

I was thinking about the penetrol application and I like the thought. Only thing about that which makes me stall on going with it is the concern of the primer bonding. I suppose if it is an alkyd then it could work. Never really tested it so I would assume you would know better Mustang Mike. Gonna be a heck of a scratch to penetrate what I am doing though. Then the two coats of Zinnser with a skim coat of something to remove imperfections on the face of the door in between. Then a couple of Sherwin Williams industrial topcoats with lettering painted on top of that. 

The safe is next. Check out how many layers of steel make for a door.


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## aaron61 (Apr 29, 2007)

cool


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## DanielMDollaPainting (Feb 24, 2011)

For the steel lintels I would just sand and apply one coat of rusty metal primer. It blends in with the brick being a flat red color. No finish coat. This seems to work fine. I painted a big long I beam peice of steel with it several years ago and it has held up fine. Most economical way to give them a new look.


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## TJ Paint (Jun 18, 2009)

The main problem with the lintels is that they will eventually bleed rust again. There is no way to stop this. Notice on the picture how it runs down onto the brick-mold?

I guess there isn't a way around this. Just something that will need to be maintained.


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## straight_lines (Oct 17, 2007)

For lintels and any other exterior metal rust destroyer. You don't even have to remove the rust, there is a chemical reaction similar to what happens with ospho. However this stuff is the best primer I have ever seen.

If it will work on beach houses or those close to salt water then you can bet you butt you won't have problems inland. 

My short write up about it is below. Really good stuff. :thumbsup:
http://www.johnsonhomeconstruction.com/remodeling-articles/exterior-painting-rust-remediation-56

Sherwin Williams can get it for you.


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## mustangmike3789 (Jun 11, 2011)

there is no way to permanently stop corroision. some coating systems will work better than or outlast others. all coatings will fail over time due to enviromental conditions, surface prep and application, most premature failures are due to improper surface prep. some coatings such as the penetrol and oil will block moisture from contacting the metal for a while, but all coatings are permeable which allows moisture and gasses to pass through them. penetrol will migrate deeper into the micro-voids in metals that most other paints will only bridge over and leave air gaps. these voids or pits in metal will be the start of a corrosion cell resulting in rust. cathodic protection such as a zinc primer will greatly reduce the rate of corrosion on metals because the zinc will be more active than the mild steel in the galvanic series, but you will need to use coatings that are compatible with zinc. this will work like the zinc anode on a boat that takes the abuse of the corrosin vs less active metals on a boat such as copper wires, stainless steel and aluminum. once the zinc anode wears away the corrosion will begin to attack the next metal in the series. this will all come down to cost and surface perp. zinc primers are a little pricey even the ones in the rattle cans like cold galv but they will outlast a typical barrier coat.


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## RH (Sep 7, 2010)

mustangmike3789 said:


> Its obvious that I probably don't know anything preventing corrosion or paint failures on those types of metals so maybe I shouldn't give any advice on this topic at this time. Don't want to offend anyone with my lack of knowledge and overkill on surface prep and product suggestions. Most of my experience is only in harsh marine environments and probably wouldn't help in this situation anyways.


Is it raining or is that just the sarcasm dripping out of your post?


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## RH (Sep 7, 2010)

FatherandSonPainting said:


> The client is hoping to be able to get someone to open it.
> 
> The door has two applications of The Must for Rust and two coats of Kem Kromic.
> 
> ...


F&SP -
Could you post some better pictures of that door? It's hard to see a difference in the before and after shots! :whistling2:
Seriously - beautiful looking work! :thumbsup:


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## AbsolutePainting (Feb 9, 2011)

We DO appreciate you Mike!!


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## mustangmike3789 (Jun 11, 2011)

AbsolutePainting said:


> We DO appreciate you Mike!!


hey thanks if you are refering to me. im not here to piss people off of try to out knowledge anyone. to be honest, i dont know jack **** about house painting besides the basics and good or bad products. these people at this forum could out-knowledge me all day long on house painting. maybe my standards are a little high or out of the norm for house painting but i do know that they are proven and accepted in the industrial field. this does not mean that they are the best ways to do things, but more as a guide to create open thinking about other standard approaches. we could easily make corrosion proof metal coatings like gold plated or platinum but it is not affordable or cost effective for any of us in this forum. my suggestions are only from my basic understanding of how protective coatings work and industry standards. before i got into paint inspection i was a tile man, carpenter, decorative concrete business owner and a restaurant manager. i got into bridge painting and accelerated from there. i had no ideal that there were standards and inspections in painting. i was like the rest of the typical people that thought that anyone can paint but i have realized that not everyone can be a painter. maybe i should have entered this forum with an introduction instead of just stepping in and giving advise but i am new to forums also so i didnt know. maybe some of you guys can cut me a little slack and accept this as my introduction. i came here from the DIY forum when i found out that there was a place for pro-painters. thanks again, mike


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## TJ Paint (Jun 18, 2009)

mustangmike3789 said:


> hey thanks if you are refering to me. im not here to piss people off of try to out knowledge anyone. to be honest, i dont know jack **** about house painting besides the basics and good or bad products. these people at this forum could out-knowledge me all day long on house painting. maybe my standards are a little high or out of the norm for house painting but i do know that they are proven and accepted in the industrial field. this does not mean that they are the best ways to do things, but more as a guide to create open thinking about other standard approaches. we could easily make corrosion proof metal coatings like gold plated or platinum but it is not affordable or cost effective for any of us in this forum. my suggestions are only from my basic understanding of how protective coatings work and industry standards. before i got into paint inspection i was a tile man, carpenter, decorative concrete business owner and a restaurant manager. i got into bridge painting and accelerated from there. i had no ideal that there were standards and inspections in painting. i was like the rest of the typical people that thought that anyone can paint but i have realized that not everyone can be a painter. maybe i should have entered this forum with an introduction instead of just stepping in and giving advise but i am new to forums also so i didnt know. maybe some of you guys can cut me a little slack and accept this as my introduction. i came here from the DIY forum when i found out that there was a place for pro-painters. thanks again, mike


I like you, but would like you more if you used paragraphs.


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## daArch (Mar 15, 2008)

Rust is a cancer. If you can completely remove it, it's cured. Otherwise all coatings and conversions will fail sooner than coatings on wood, brick, concrete, etc.

Do as Dean says, give a reasonable warranty, and make sure they realize it's all about maintenance. 

I was impressed with rust converters (with wire brushing and sanding), but also disappointed rust came back between one and three years. 

BTW, sand blasting is one of the mot effective ways of removing the rust - as long as it has not eaten REAL deep.


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## mustangmike3789 (Jun 11, 2011)

TJ Paint said:


> I like you, but would like you more if you used paragraphs.


 my mom was an english teacher and is now an assistant principal so i do know how to use paragraphs but.... i wasnt the best student.


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## Bender (Aug 10, 2008)

Yeah Mike What TJ said

Welcome to the forum! 
I always enjoy reading what guys like you and NACE say. Good Stuff:thumbsup:


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## TJ Paint (Jun 18, 2009)

mustangmike3789 said:


> my mom was an english teacher and is now an assistant principal so i do know how to use paragraphs but.... i wasnt the best student.


I need all the help I can get to taking in the great quality info you are providing


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## mustangmike3789 (Jun 11, 2011)

Bender said:


> Yeah Mike What TJ said
> 
> Welcome to the forum!
> I always enjoy reading what guys like you and NACE say. Good Stuff:thumbsup:


 we sometimes only say what the "book" tells us to say vs actual practical hands on experience. i too have had to deal with other inspectors that are ranked higher than me that have never touched a paint brush. i know that some of the things on paper dont work in the real world. paint application in a lab or in perfect shop conditions cant always be managed on an actual job site with dust, humidity and idiots working against you.


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## Ultimate (Mar 20, 2011)

researchhound said:


> F&SP -
> Could you post some better pictures of that door? It's hard to see a difference in the before and after shots! :whistling2:
> Seriously - beautiful looking work! :thumbsup:


 I intend on dropping by this week and spending a couple of hours. I will see if I can get some better shots. 

My sign in the window on the main street of Southport is not making things move any faster. Just sayin'.


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## nEighter (Nov 14, 2008)

Try this.









http://www.google.com/products/cata...a=X&ei=vQBSTompMZO3twef8qieBw&ved=0CEgQ8wIwAg

I am doing my truck's frame in it. I PROMISE YOU you will love this stuff. Dries quick too.


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## 4ThGeneration (Apr 17, 2007)

nEighter said:


> Try this.
> 
> 
> 
> ...


Dries quick as in the spray unit or in mid stroke?

or


Works well during app and dries quick after?


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## MaizeandBluePainter (May 7, 2008)

*cold galvanizing compound*

I use a product called "Cold Galvanizing Compound" which I think is made by Rustoleum. You can spray it on galvanized metal, because it is 98 percent zinc. 

It also works for other metals (zinc protects steel from rusting as somebody described above.)

And you can topcoat it with whatever water-based paint you're using.

Simplifies the process of painting metal a bit.

(link: Amazon.com: Rust-Oleum 7585838 Professional Cold Galvanizing Compound Spray Paint, 20-Ounce: Home Improvement)


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## lbass215 (Aug 25, 2011)

ok I skipped most of page two you guys went to a much better paint school than me. I was just wondering if Peel bond sticks to metal and if so would putting 40mils of glue and primer slow down rusting time?


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## straight_lines (Oct 17, 2007)

IDK about slow it down, but acrylic usually bleeds through if its not made for rust. Even then it doesn't perform nearly as good as solvent based primers.


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## Ultimate (Mar 20, 2011)

Finishing coats applied to the entry door. Without the use of bondo to perfect the decades of pitting etc, it looks good indeed. Lettering to be painted and final pics to come. 

The safe was opened, with treasure in the form of sterling silver to be found. Pictures to come of that as well. 

Scope has been increased to coating of the safe, stripping the ceiling, repairing the walls and application of paint there as well. Followed by the rest of the building after completion of construction bringing things up to code. Will proceed with the safe with an initial application of penetrol over all surfaces. 

Good guy to work for.


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## straight_lines (Oct 17, 2007)

John is that downtown somewhere?


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## Ultimate (Mar 20, 2011)

In between The Pharmacy and the State Port Pilot building.


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## RCP (Apr 18, 2007)

Awesome project!


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## RH (Sep 7, 2010)

Great looking door job John! looking forward to seeing the safe as it progresses and to hearing about the "treasure". Sounds like a neat story. 
Always nice to have a job expand with a good customer. :thumbsup:
Dan


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