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Greetings from Az,
The Grade D paper, #17 wire and flashings are almost up, it’ll soon be time to be an amature plasterer. YIKES!
A few questions:
Does anyone use a fiber addmix for the scratchcoat?
On a 3-coat, do ya start from the top or the bottom ?
If no control joints are used, where do ya stop at the end of the day?
Can anyone recommend a book or article to help this “newbie” from TOTALLY screwing up this 3 coat job ?
Basically, I need all the help and advice I can get… 🙂
Thanks in advance,
Frank
Replies
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Frank
I admire your courage... stucco is 50% labor and 50% art and background ability. The scratch and brown coats will probably go OK but that final coat is the one that will make the job look like an amature did it. Take a piece of 4x8 plywood and cover with paper and wire. Once the sheet has been braced in a vertical position, try to cover it with stucco, all three coats, and decide if you might be better off hiring this out to a subcontractor. You will need someone to mix and carry too or your definitly going to have problems.
*Definitely think about the amount of labor required here. Why? Because the stucco won't wait for you while you busy yourself with something else. Even with a large crew of friends, you'll have a wall that looks like hundreds of little patches if your "crew" are not very proficient with a float.Gosh, (no offense) but if you A)decide to go ahead with this; B) live in CA, give me a call so I can watch. LOL
*The big problem you've got is getting the brown coat to stick to the wire. There are only three ways to do this-- practice, more practice and much more practice. I don't think you will be able to do it. I can plaster over expanded metal, barely, but not wire lath. I think you are biting off more than you can chew.
*Uh-oh. We've just started our first plastering project on expanded metal lath, and have done the first brown coat. It keyed in fine and I have no doubt it is stuck good -- what do you know that I should have known??BTW, we used the wood fiber-reinforced "Red Top" plaster and worked top to bottom - quickly! The plaster starts to heat up and harden in short order.
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uh...guys...
The scratch coat is what goes over the wire. It's the brown coat that gives the wall the straight and plumb look.
The first thing that needs to be known about this guys problems is where is the plaster is being installed.
Is he talking about exterior stucco?
Interior gypsum plaster?
These are two very different beasts.
From his message header he would seem to be talking about exterior stucco....(leaves you felling better, doesn't it Andrew).... ;^)
I have seen fiber used for stucco but it really isn't needed. Stucco has been applied for thousands of years without it.
When doing stucco it's usually best to start at the top. The reason is because you may (read probably will) drop a bit of plaster as you are working. If you were to start at the bottom you may drop a bunch of plaster on areas you have already finished below you......causing a big pain right in the temple.....(headache!!!!)
When you're at the end of the day you can stop anywhere on the wall (for scratch and brown coats). When you do stop you need to cut the end of your run square. This will allow you to start the next day up against a flat edge and it helps you to hide the joint. For the finish coat you really need to end at a natural break. Find a window or, preferrably, an inside or outside corner.
For books....well....I aint gonna spam this board.....sorry
Brian Ewing
OrnamentalPlaster.Com
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Oh, this is just another example of an attempted digression. When you get to reading, it is easy to forget what the topic was in the first place!
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Frank;
The wire lath used for stucco reinforcement goes up in one direction.Look closely and you'll notice that if you orient the lath in a certain direction you will create hundreds of little troughs which the stucco will lie in.Good luck!
Don L.
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Are you trying to say that I have had so much trouble because I forgot the scratch coat? That could explain things.
Seriously, what I intended to say was that it is difficult to get the scratch coat to hang on wire lath and it is difficult to get the brown coat flat. Although I do fairly well with expanded metal lath which does hold the mud (if it's not hung upside down) I can barely do it with wire lath.
On the first house I had stuccoed, I hired a plasterer, who let me do the really hard work -- carrying hod. It seems that buckets have almost done away with the art of carrying hod, and I can't say that I'm sorry.
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We were considering doing the exterior stucco ourselves, and are so glad we didn't. Time: a six person crew did the entire scratch coat on our small 1700 sq.ft.house in one day, not counting the dormers. Safety: it was hard dangerous work on the dormers and gables, and lots of blood on the mesh from cuts. Guaranteed results: they had 30 years experience knowing how to mix and apply and not create problems. My advise is to hire the best - - maybe you can trade some of your time for theirs to save $.
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Another tip if you've never done plaster or stucco -- make sure you rinse your mixer well between batches, likewise for buckets & wheelbarrows. Partially reacted mix or mixwater will accelerate the reaction in the following batch. I don't know why, (anyone know?) but it does. It's a real bummer when you get a fresh load mixed and it starts going off before you get it onto the wall. Likewise, a lot of bad results on interior plaster is directly traceable to dirty water.
If you're interested in fiber, Western one-coat is an option for stucco. Some folks won't compare it to a three coat job, but it does work. For interior work, it's hard to beat Red-top wood fiber. If you keep the mix around 12 to 18 shovels of sand per bag (varies with personal preference), it's incredibly strong.
And be careful with the metal lathe. Really.
*With the Red top wood fiber, what exactly is the purpose of the sand? Aggregate? Filler? Can you do without it if, say, you're out of sand on a holiday but want to finish the brown coat? (The scratch coat on lath is supposed to be "neat" tha package says -- took me a little while to figure out that meant no sand...)
*Dontcha hate it when people ask questions they can answer themselves. I suddenly remember that I had the Web, that amazing resource, at my fingertips. From the USG site:> <> ® <> Fiber Plaster>> Is a gypsum plaster containing fine particles of selected wood fiber. It is strongly recommended as a scratch coat for metal lath, but can be used on all standard laths and masonry. Wood fiber plaster normally requires adding only water. A 1 cu. ft. volume of sand per 100 lbs. of plaster must be added when machine applied or used directly on masonry, and may be added when used as a scratch or brown coat. Complies with ASTM C28.So skipping the sand is more expensive, like not diluting your antifreeze. Neat gives about 30% less coverage but is stronger (1750 psi v. 1400). It may not dampen sound as well, and perhaps is more prone to cracking??? As to why partially cured plaster acts as a catalyst for a fresh batch, I'm curious too.
*We tried the wood-fiber "neat" per the directions on the package. I'm a little puzzled by the instructions, still, because of the results we got. The material seemed stronger, "tighter", less prone to cracking, easier to apply, denser, easier to get a good brown coat over, just all-around better with a little sand added. No idea why, it just worked better. Anybody know?Oddly enough, the antifreeze analogy may hold :) since you actually do need to add water to antifreeze for it to work properly.Still wondering why dirty water sets a fresh batch off so fast. Any ideas from old-time plasterers?Back to the original question, re: working top to bottom or bottom to top -- we work left to right, full height. This allows us to work without being concerned with a visual seam -- if you work up or down, your reach across the wall is limited by the size of your crew. On a large wall, you might get a joint that you could see when you're done. By working left to right, even with a small crew, you don't need to worry about leaving a visible joint.
*Good point! The instructions are cryptic, but what i finally realized they actually say is that only the -scratch- coat is recommended neat. The brown coat could be something else, fiber+sand, etc. Adding sand is certainly attractive for workability.I think I remember that gypsum plaster is made from pulverized gypsum rock, when it sets the particle reassemble into a monolithic piece of rock. Perhaps the contaminants provide "nuclei" for the gypsum to begin reforming more quickly, kind of like seeding a cloud brings rain.
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Left to right is the way to go. As for the reason dirty water or left over particles from the previous mix causing the new batch to flash, it's a chemical thing. Something akin to crystals forming in an almost super saturated solution of salt or sugar with the addition of any little bit of foreign matter. On the art of plastering
(an almost lost art I must admit) I must agree to these percentages= 30% sweat labor; 50% learned OJT (aka experience) and 20% love of the work and desire for pride in your work. It's just something that's not learned by doing it once or twice. Old time plasterers are equally at home with cement plaster, premixed stucco or interior gypsum and lime white coat plaster.
If it takes years to become proficient in the art of plastering, how can anyone describe the process and all its nuances in just a few paragraphs???
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Greetings from Az,
The Grade D paper, #17 wire and flashings are almost up, it'll soon be time to be an amature plasterer. YIKES!
A few questions:
Does anyone use a fiber addmix for the scratchcoat?
On a 3-coat, do ya start from the top or the bottom ?
If no control joints are used, where do ya stop at the end of the day?
Can anyone recommend a book or article to help this "newbie" from TOTALLY screwing up this 3 coat job ?
Basically, I need all the help and advice I can get... :)
Thanks in advance,
Frank
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True! And that's the difference between an acceptable amateur job and a breathtaking professional one. The problem is, with the practitioners dying off (literally), you gotta do what you can.