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  #1  
Old Wed 31 October 2007, 19:13
ldorta
Just call me: Leandro
 
Curitiba (PR)
Brazil
Finish cleaning, filling, painting, powder coating, etc.

Friends, looking into my Y car, I found some rust on it, so I'll need to paint it as soon as possible. What do you use to prepare the surface (before the paint)?
Gerald, in a previous post I read (don't remember where) that you use kind a filler on the corners, is that right? Which filler is this?

Thanks
Leandro
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  #2  
Old Thu 01 November 2007, 01:13
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
Leandro, you have not got enough rust yet! Seriously . . . . .

There are two secrets for getting paint to grip to steel:
- there must be no grease or oil
- the surface must be slightly rough

A little bit of rust proves that there is no oil . . . . and it makes the surface rough. You do not want too much rust - the paint must get through to the steel at the bottom.

The filler is acrylic based (definitely not silicon). It cleans and shapes with water or a wet sponge/finger. You put this on after the first coat of paint.

Our paint process is:
1. Remove all loose rust
2. Remove all sharp edges & points. (paint does not stick to a sharp edge - its surface tension pulls it away)
3. Degrease - we use a water-soluble kerosene, rinsed with water
4. Apply primer paint - we use a slightly acid paint that roughens/etches the metal.
5. Do the acrylic filler work
6. Apply second coat of primer over the filled areas.
7. Finish paint - two coats
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  #3  
Old Thu 01 November 2007, 05:54
Marc Shlaes
Just call me: Marc
 
Cleveland, OH
United States of America
Send a message via Skype™ to Marc Shlaes
Gerald,

I am not familiar with the term "acrylic filler". Is there a brand name that I might be able to find on the internet so that I might be able to find something equal to that here in the US.

Thanks.
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  #4  
Old Thu 01 November 2007, 06:40
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
I saw them at your Home Depot, but none of your brand names were familiar to me. All in tubes that fit into caulking guns - the word "acrylic" is prominent and the word "silicon" is absent, with other words containing "paint". Our popular brand is PaintersMate, similar to this:
http://www.countyconchem.co.uk/docs/...intersmate.htm
but doesn't carry the Dow Corning logo any more.
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  #5  
Old Thu 01 November 2007, 07:54
Marc Shlaes
Just call me: Marc
 
Cleveland, OH
United States of America
Send a message via Skype™ to Marc Shlaes
Oh, that is what we call "painter's caulk". I never used that on anything metal before. I typically use that for caulking seams prior to house painting. For metal work, I have always used polyester or epoxy fillers.

I never would have thought.
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  #6  
Old Thu 01 November 2007, 09:19
domino11
Just call me: Heath
 
Cornwall, Ontario
Canada
Gerald,
Is the application of the filler just for looks, or is it for eliminating dust accumulation etc? Would Marc's polyester or epoxy type fillers be a better choice? Maybe add a little strength as well to the assemblies in question?
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  #7  
Old Thu 01 November 2007, 09:44
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
It is mainly for paintability which firstly is for corrosion protection and secondly for looks. . . . . .

Spray paint does not blow into the corners or around the tips of butt joints. But moisture loves those crevices and that's where the serious corrosion starts - you can't get in there to fix the corrosion either. The old way of stopping corrosion on dump and garbage trucks (as examples) was to weld along the full length of the joint; which caused massive distortion but longer life due to less corrosion. The popular way these days is to use space welds and filler in between. Polyester or epoxy is not necessary - we don't want any strength from the filler, other than to support a coat of paint that flows smoothly from one surface to the next.

You guys have access to Sika over there. It was mainly Sika that came and taught us to use fillers instead of full welds - and tried to sell us all their fancy fillers: http://www.sikaindustry.com/ind/ipd-transoem.htm But we discovered that the cheap acrylic stuff from the local hardware store does as good a job of filling.
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  #8  
Old Thu 01 November 2007, 11:14
smreish
Just call me: Sean - #5, 28, 58 and others
 
Orlando, Florida
United States of America
...and Gerald knows dump trucks! Great point.
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  #9  
Old Thu 01 November 2007, 12:11
Leko
Just call me: Leko
 
Kaukapakapa
New Zealand
Filler FYI

Hello all, I'm Leko, and you'll soon find out who I am, but I thought I'd jump in here...

I haven't seen anybody talking about powder coating their MM's but I'm sure the day will come (nudge, nudge SMR.)

I asked my powdercoater if there was any filler that could handle being coated, and he said that JB Weld holds up to the the oven temps fine and coats well, also this stuff called Lab Metal which works just like body filler comes in a high temp version that can be powder coated.

Even if you're just going to paint and want to make your machine look more polished (or if you're welding isn't as pretty as could be) you can always fill fillets or seams with Bondo and sand.
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  #10  
Old Thu 01 November 2007, 14:33
smreish
Just call me: Sean - #5, 28, 58 and others
 
Orlando, Florida
United States of America
Leko,
Good to see you chimed in. I have called Powder Tech here in Orlando and they are putting together pricing at this time. They have an oven 10 x 10 x 20, so I can take the machine to them assembled if I wanted. Who knows, it's stiff enough to be forklifted - moving would not be a problem.
...and I really like the lab metal stuff. Mmmmm...good ideas. Thanks
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  #11  
Old Thu 01 November 2007, 23:34
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
The filler is optional - it adds nothing to performance.

If done neatly, it adds a lot to re-sale value
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  #12  
Old Fri 02 November 2007, 11:24
WTI
Just call me: James
 
Detroit (Michigan)
United States of America
We have a powder coat system, but our oven is way too small for how large most of the MM parts are!

I guess we would have to weigh the cost of having it done by an outside shop vs. the few hundred dollars in buying a heat lamp:

http://www.caswellplating.com/powder/caswell_lamp.html

If I thought we would ever use the heat lamp again, I would get it in a heartbeat. But in 8 years of our shop running, this is the first time our parts were larger than our oven.

Another idea was to just melt the powder with a regular heat gun. It is not like we are going to enter the MM in a show, so if we overheat a few spots and the finish runs, who cares? All we want is the great protection powder coating provides.
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  #13  
Old Fri 02 November 2007, 12:00
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
Why not regular automotive spray paint as opposed to powder coat?
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  #14  
Old Fri 02 November 2007, 12:19
smreish
Just call me: Sean - #5, 28, 58 and others
 
Orlando, Florida
United States of America
Oh, I love paint. Most likely this will be painted. I just thought I would check into pricing for giggles.
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  #15  
Old Fri 02 November 2007, 14:47
domino11
Just call me: Heath
 
Cornwall, Ontario
Canada
Gerald,
I remember that someone posted links to some Farm implement paint. This comes in Mechmate blue (sometimes called Ford Blue I think ) This is cheaper than automotive paint but still very durable and more easily obtained. This is what I will be using. This can be sprayed or brushed with equally good results.
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  #16  
Old Fri 02 November 2007, 15:31
Marc Shlaes
Just call me: Marc
 
Cleveland, OH
United States of America
Send a message via Skype™ to Marc Shlaes
It was J.R.

I cut and pasted his post: (below)
================================================== ====
I think this might help others. I used paint from Carquest, it was $30 per gal. It takes forever to dry, to touch 3 hrs. Completely I don't know yet it's only been 3 days. I found a better paint, I wish I had found it a week ago.

Paint http://www.agrisupplyco.com/cgi-bin/...0000&l=1#Order

Reducer http://www.agrisupplyco.com/cgi-bin/...0000&l=1#Order

Hardner http://www.agrisupplyco.com/cgi-bin/...0000&l=1#Order
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  #17  
Old Fri 02 November 2007, 19:51
WTI
Just call me: James
 
Detroit (Michigan)
United States of America
Quote:
Originally Posted by Gerald D View Post
Why not regular automotive spray paint as opposed to powder coat?

Powder coat is extremely thick and durable paint. Boat trailers that spend much of their time submerged in water are always coated with it around here to prevent rust. It melts into a plastic coating and completely covers the surface without runs or drips. Because it clings electrostaticly, it coats the inside of parts that might otherwise be un-sprayable. Usually no primer is required and there are no VOCs.

You can reuse what little "over spray" there is, so it is almost 100% usable.

And maybe the best part, it is rock hard dry as soon as it cools.
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  #18  
Old Fri 02 November 2007, 20:08
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
Yes, I know all the salestalk of powder coat (we have it here too), but why aren't any cars finished in powder coat?

(PS. I don't know of any powder coated boat trailers here - the decent ones are either hot-dipped galvanised or painted. We have a popular trailer range over here that is notorious for rust - I think it is (badly) powder coated)
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  #19  
Old Fri 02 November 2007, 22:07
tpworks
Just call me: Tom
 
Atlanta, GA
United States of America
Hey Guys in the US,
For filling in minor imperfections this works great on wood or metal.
Can be wet sanded and dries virtually in minutes in thin applications.
http://www.bondo.com/catalog_item.asp?itemNbr=736

Tom

P.S.
Another great but expensive product is POR-15 it loves rusty metal www.por-15.com

Last edited by tpworks; Fri 02 November 2007 at 22:34..
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  #20  
Old Sat 03 November 2007, 03:37
smreish
Just call me: Sean - #5, 28, 58 and others
 
Orlando, Florida
United States of America
Oh my, look what Leko and I started! Bondo (or my favorite) Everclear polyester which is used in boat hull mold final finish is my favorite choice It's lighter weight (easier to sand) than bondo, and it's grey! Not that darn orange color...makes it easier to paint over without to much extra paint/primer. Now, it's time to go to the shop and start working on those rails!
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  #21  
Old Sat 03 November 2007, 18:05
cbboatworks
Just call me: Gene
 
Wilmington NC
United States of America
Hello Guys

I am a Boat builder and a painter,My choice of paint would be Imron 3.5 HG. I paint all of the boats that come through my shop with it. you can get a spay-able gallon for around $60.00 just remember that this is one of the most toxic paints known to man so if you use it use a good respirator. I will post a picture of the finish product that was sprayed with it. Gerald if the picture is taking up to much space please remove it. if anyone is interested in more info on this paint please PM me and i will help all that i can. Thanks

cbboatworks@aol.com

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  #22  
Old Sat 03 November 2007, 19:05
Marc Shlaes
Just call me: Marc
 
Cleveland, OH
United States of America
Send a message via Skype™ to Marc Shlaes
Gene,

That looks beautiful! Does it come in MechMate / Ford Blue?
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  #23  
Old Sat 03 November 2007, 21:54
tpworks
Just call me: Tom
 
Atlanta, GA
United States of America
Quote:
Originally Posted by smreish View Post
Oh my, look what Leko and I started! Bondo (or my favorite) Everclear polyester which is used in boat hull mold final finish is my favorite choice It's lighter weight (easier to sand) than bondo, and it's grey! Not that darn orange color...makes it easier to paint over without to much extra paint/primer. Now, it's time to go to the shop and start working on those rails!
Go ahead, knock bondo, but you can't beat POR-15 it covers all the bases, even fillers that withstand 2000 degrees. I didn't think we were trying to float a boat. I thought heavier was better for this project? But maybe that's just me.

Tom
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  #24  
Old Sun 04 November 2007, 00:03
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
Okay, let's get back to basics. The MechMate is not meant to be used by dipping into lakes or the sea. It is a piece of workshop woodworking machinery like your table saw. The accurate rail (and gear) surfaces are not going to get any paint or powder so we are going to keep the machine indoors where it will stay dry. We do not have to discuss the most corrosion-resistant paint systems - the demands on the paint are very low.

Powder coating is not for the average DIY guy. I think the main reason I dislike powder coating for this project is because it only gives you one chance at welding. After it is powder coated you are locked out from welding again. I like to be able to weld a bracket a month later without worrying how to touch up the finish. A basic paint system gives me the most freedom to modify to taste.

For those that don't know it yet, the "Ford Blue" was chosen because our local hardware shop stocks it in aerosol cans. (rattle cans) On our machine, only the base table was painted by spray-gun. Everything else (gantry,y-car,z-slide,motor-plates,etc.) was done with caulk and rattle cans from the corner hardware shop. I can decide now to move a bracket and within an hour it will look brand new again.
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  #25  
Old Sun 04 November 2007, 07:05
Marc Shlaes
Just call me: Marc
 
Cleveland, OH
United States of America
Send a message via Skype™ to Marc Shlaes
I do intend to paint, not powdercoat for the exact reason Gerald stated. I can assume that since I will have built it myself, I will probably want to modify something later on.

But my shop is in a coastal area - fresh water - not even salt water - and I have a VERY REAL problem with rust. That is why I posted my secret sauce T-8 from Boeshield in a post a few months ago. I will probably use the very best primer I can find for rusty environments. I didn't know about the POR-15 products. I appreciate that link and endorsement very much.

For paint, I will stick to Ford blue because "Gerald says so" and frankly that is quite enough for me! I might, however, buy marine paint if it comes in the right color. I certainly don't want to be sandblasting my machine in three years. If good paint keeps it making money, then the price is nothing in my book.

Just my two Cents / Rand / Rupee, etc.
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  #26  
Old Sun 04 November 2007, 07:17
cbboatworks
Just call me: Gene
 
Wilmington NC
United States of America
Quote:
Originally Posted by tpworks View Post
Go ahead, knock bondo, but you can't beat POR-15 it covers all the bases, even fillers that withstand 2000 degrees. I didn't think we were trying to float a boat. I thought heavier was better for this project? But maybe that's just me.

Tom
The paint that I reccommended is an industrial paint, used in theme parks and industrial machines. I use it on boats b/c it is such a hard and durable paint. It is not really intended for boats.
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  #27  
Old Sun 04 November 2007, 07:20
cbboatworks
Just call me: Gene
 
Wilmington NC
United States of America
Quote:
Originally Posted by Marc Shlaes View Post
Gene,

That looks beautiful! Does it come in MechMate / Ford Blue?

Hello Marc

You can get it mixed in any color.
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  #28  
Old Sun 04 November 2007, 08:17
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
Marc, I live near the sea, where the salty spray of the jumping sharks blows over us. Also, I build equipment that gets dunked with corrosive sauces - ketchup being one of the worst. And the biggest lesson I have learnt for anti-corrosive painting is that the quality of the final paint has nearly nothing to do about the anti-corrosion. Steps 1-6 in post number 2 is what counts.
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  #29  
Old Sun 04 November 2007, 08:33
Marc Shlaes
Just call me: Marc
 
Cleveland, OH
United States of America
Send a message via Skype™ to Marc Shlaes
Agreed. For me, it seems that the very hardest thing is the degreasing step for steel that still has mill scale. Removing all mill scale is just not practical. Therefore there are billions of places for the oil to hide. I am not looking for magic but a little help from the primer and paint doesn't seem to hurt.
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  #30  
Old Sun 04 November 2007, 08:54
gmessler
Just call me: Greg #15
 
Chicago IL
United States of America
Hi Marc,

To help you out about the grease thing. When was trying to get tape to stick to the parts for marking purposes I found that a cheap quick fix was to spray brakleen on the metal and the tape stuck very well. The brakleen doesn't leave any residue and dries fast so I would imagine that primer/paint would stick well after cleaning. I also gave a quick shot of it to the inside of my x channel to clean off the gobs of threading oil/metal chips. It worked exceptionally well. It even cleaned out the tight inside corners at the ends.
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