Page 1 of 2 12 LastLast
Results 1 to 10 of 11

Thread: How Many Coats Of Clear

  1. #1
    Join Date
    Jun 2005
    Location
    Carol Stream, IL
    Posts
    18

    Default How Many Coats Of Clear

    I'm Rebuilding a 1972 GTO And Have Been Debating With My Future Father-in-law was wondering how many coats of clear people would suggest. he wants to do 10 i say 5. please help. Karl
    Last edited by underworldowner; 06-30-2005 at 11:33 PM. Reason: spelling

  2. #2

    Default

    It really depends on what kind of paint you're using. In the old days of lacquer, it took many, many coats to get that deep shine because you would sand each coat, then spray another, then sand, then spray until you had sufficient film thickness. Since most of each layer was sanded off, it didn't really build up too much.

    With modern basecoat/clearcoat urethanes, however, too many coats is a very bad thing--it leads to cracking, delamination and other problems related to film thickness. Paint that is too thick is not very durable.

    In most cases, 2 coats of basecoat are sufficient to make sure the color is uniform, then 2-3 coats of clear which is wet sanded and buffed to a high shine is ideal. More than that and you run into problems. Each paint manufacturer will have recommendations on film thickness and the number of coats to apply, and I suggest you follow them--they know their product better than anyone and actually want you to have the best possible result.

    I think your father-in-law is thinking of lacquer, which is old technology and virtually impossible to get today. With modern paints, too much clear is too much of a good thing and won't improve your results in any visible way. As long as you have enough clear on it to keep from cutting down to the base coat when you wet sand, you'll have a quality paint job with a deep shine. More clear won't do anything to improve that--it's all in the surface prep (getting it straight) and in the final sanding/buffing to make it perfect.

    Hope this helps.
    Matt Harwood
    Cleveland, OH
    My 1941 Buick Century sedanette restoration
    If you have a '41-42 Buick with dual carbs, also be sure to visit The Dual-Carb Registry
    Build a V8 Ranger!

  3. #3
    Join Date
    Jun 2005
    Location
    Carol Stream, IL
    Posts
    18

    Default

    thank you it helps alot hopefully he will give up on 10. as for the clear it is sherwin williams ultra 7000 clear. we thought about using HOC but we both have bad reactions before.

  4. #4
    Join Date
    Feb 2005
    Location
    texas
    Posts
    245

    Default

    With HOK or PPG or X-otic clears (which is what I use) for the final clear coat I shoot 3 coats. That way there is a bit of a safety buffer to discourage wet sanding through to the base coat. A word of caution, when wet sanding be very careful around edges it is easier to sand through than you mihgt think. Don't ask how I know. Al

  5. #5
    Join Date
    Jun 2005
    Location
    Carol Stream, IL
    Posts
    18

    Default

    i know what you mean i've burned quite a few clears in the past few years. i like the ppg base but i prefer the clear from sherwin. we haven't decdided but we might use standox. instead

  6. #6
    Join Date
    Feb 2005
    Location
    texas
    Posts
    245

    Default

    Never tried the SW clear. I have used some of thier (SW) industrial paint (Corothane) on dams and bridges and it is a good product. Have you checked out the PPG 3000 clear? I recently used it for the first time. It laid down smooth and the really cool thing is you can get on it for cutting and buffing in a matter of a hours. It is a 2 part clear and catylist, the reducer is built in so you dont have to add any. It comes in slow to fast for whatever temperature range you are in. Ill have to look at the SW clear. Im curious why you prefer it. AL

  7. #7
    Join Date
    Jun 2005
    Location
    Carol Stream, IL
    Posts
    18

    Default

    i prefer the sw clear because i've have some problems with ppg. i had to redo 5 cars because of some bad reactions between the base and clear. good thing for their warrenty. they covered the whole thing. since then i use ppg base and sherwin clear.

  8. #8

    Default

    Quote Originally Posted by underworldowner
    i prefer the sw clear because i've have some problems with ppg. i had to redo 5 cars because of some bad reactions between the base and clear. good thing for their warrenty. they covered the whole thing. since then i use ppg base and sherwin clear.
    No offense, but that sounds like a recipe for BIG problems. Mixing and matching brands can lead to all sorts of problems. Unless you're an experienced painter, leave the chemistry to the paint companies and stick to a single system from one manufacturer.

    For more information, I'll refer you to The Basics of Basics by a fellow named Brian Martin. He's been a body shop owner and a paint company rep, so he knows exactly what he's talking about. One of his biggest points is to avoid being a "junior chemist" and trying to make products from different manufacturers work together--whether because you think you know better than the scientists or just to save money. In his experience, flaws in paint materials are virtually unheard of (very rarely are there "bad batches" of auto paint), and most failures can be traced back to the painter (this is not to suggest that underworldowner didn't get a bad batch as the source of his problems with PPG).

    Here's an exerpt from an editorial he's written:

    ____________________

    Listen, the subject of mixing products comes up here often. I put this together to clear up why I feel the way I do about the subject. I by NO means am saying this to anyone and it is not personal. In fact, I don't even remember a particular post or person saying anything. It just comes up from time to time.

    Rules, Rules RULES...
    By Brian Martin

    Rules, rules, rules, so many rules. Use this don’t use that. Sand this, don’t sand that. These companies must think we are stupid right? They tell us to buy their products only. Of course they do, so they can make money off of us, right?

    That is how many people feel. They mix and match products thinking they can out smart the chemists that created the product!

    The manufacturer spent hundreds of thousands of dollars, possibly even millions developing the product. They did EVERYTHING possible to make it perform it’s best. Heck, if they found it worked better if you painted it while standing on your head, THAT would be in the tech sheet!

    Did you know that most of these products you use have a lifetime warranty? That’s right the manufacture will stand behind their primers, paints, and clears for your LIFETIME. Now, as a DIYer you can’t have this warranty. What makes the difference between the warranty YOU have (usually none) and the lifetime warranty a shop may have? The training, that’s what. The manufacturer has classes for the painters to go to. He then takes a test, if he passes, the manufacture knows that he understands the procedures and proper product choice. The manufacture has learned that it is likely the painter will use the product properly and it will perform as expected. The manufacture puts hundreds of millions of dollars on the line with this warranty. They know they can, if the product is used EXACTLY as they have instructed on the tech sheet.

    I have always been the kind of guy to follow instructions. Even before I had the training I used the products exactly as I was told to. I am sure this accounts for the very few failures I have had in the 28 plus years I have been doing this work.

    Five of those 28 years I was a paint rep. If there is one singular thing I came away from that job with it would be importance of following the recommendations. As a rep I visited hundreds, possibly thousands of shops. These shops were in every shape and size. From one with seven frame machines and five paint booths doing a million dollars of business a month, to a one man shop with two stalls.

    Among these shops there was a very distinct pattern, the ones who went to tech school, had only ONE brand of product on the shelves, and REFERRED to the tech sheets, had fewer problems. Most of these shops had NO problems, EVER.

    They were open to hear about new products and ready to learn about how to make any product or tool perform better. Oh yeah, and they made more money.

    Then, there was the “dark side”. These were the shops that would buy any product, any brand, just to save a dollar. Their shelves were covered with so many labels, it looked like the cans of soda and beer in a Quikie Mart cooler.
    If, and I mean a BIG if, you could get them to a tech class, they were disruptive and later told me how they “could have taught that class.” They were quick to tell you how smart they were and how the paint company didn’t know jack about the “real world”. These shops took up about 99% of my trouble shooting time. They didn’t have little “how can I get this primer to dry faster”? sort of problems. They had TOTAL catastrophic failures! I was the first one they called because we must have put out a “bad batch” of product.

    I tell you this only so you can understand where I get this passion that I have for using products properly. It was like watching a basketball came where one of the teams were wearing wet jeans and cowboy boots! After a while you wouldn’t even have to watch, you would know what the outcome was going to be.

    Most product data sheets can be read in a few minutes. They are available on line, as well as in the store where you bought the products or even many are available on “Fax Back” right over your phone.

    Get proper mixing containers. Be sure the solvents used match temperatures of the booth. Double check to be sure you have ALL the components (and enough of them) BEFORE you start so you don’t find yourself tempted to be “creative”.

    The three most important things and the most common cause of failures are as follows:
    1. Mix the proper components accurately .
    2. Use the correct solvent for the temperature.
    3. FOLLOW THE RECOMMENDED FLASH TIMES.

    All this info is on the product data sheets, use them.

    Painting can be difficult, there are things that are quite honestly out of your control. So, why not do EVERYTHING that IS in your control correctly.

    __________________________

    For these reasons, I'd take Brian's advice and stick to one brand from start to finish. Why add another variable to such a complex, expensive and time-consuming process?

    Hope this helps.
    Matt Harwood
    Cleveland, OH
    My 1941 Buick Century sedanette restoration
    If you have a '41-42 Buick with dual carbs, also be sure to visit The Dual-Carb Registry
    Build a V8 Ranger!

  9. #9

    Default

    sherwin-williams ultra 7000 clears work great over ppg bases. i have sprayed that combination many times with no problems. i like to spray a light tack coat then spray two medium coats. i let the clear dry, sand with 2000 grit wet paper, and buff. produces an awesome glossy finish.

  10. #10
    Join Date
    Feb 2005
    Location
    texas
    Posts
    245

    Default

    Basicly I agree with the read the instructions philosiphy. I have done things mixing brands after other people have told me they tried it and it worked. Example PPG clear over HOK. X-otic and HOC are virtually the same. Having said that. One thing that can get you into trouble is not observing the time frames (windows) between coats, or sanding if things sit around. I have intermixed PPG, HOK. and on a limitied basis (1 base coat) Matrix. No bad results. I may try the Sherman Williams if the price is right. Al

Similar Threads

  1. Multipule Coats of Clear?
    By Sho Nuff in forum Powder Coating
    Replies: 0
    Last Post: 02-22-2010, 06:10 PM
  2. Question about Pearl and Clear coats
    By jpoiron in forum Ask Eastwood
    Replies: 3
    Last Post: 09-28-2009, 05:14 PM
  3. 2nd Coats
    By Rufus in forum Powder Coating Archives
    Replies: 9
    Last Post: 09-13-2006, 08:02 PM
  4. Clear coats
    By mwr2452 in forum Powder Coating Archives
    Replies: 3
    Last Post: 06-27-2006, 09:59 AM
  5. Question about clear coats
    By KevinC in forum Powder Coating Archives
    Replies: 4
    Last Post: 08-20-2005, 01:12 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Follow Us