How many coats

[strtjoints]

How many coats of orange red engine pain is normal for repainting, I have primed it as well . All paint is dupli color. Im restoring my 719. Also I have engine clear coat . how many coats of each do y'all think? Thanks

[undee70ss]

Im not a painter so I really don't know. If I had to guess it would be 3 coats.

[sweepleader]

I am not a painter either. I stop when it looks right. I make sure everything is covered and the surface is even and smooth. I have not painted an entire saw yet so bear that in mind. More looks better and seals better, too much looks bad and chips easier. Leon will be back soon, HE is a painter.

[onlyhomelites]

Aug 4, 2017 15:03:13 GMT -5 strtjoints said:

How many coats of orange red engine pain is normal for repainting, I have primed it as well . All paint is dupli color. Im restoring my 719. Also I have engine clear coat . how many coats of each do y'all think? Thanks

Back from vacation! I typically use 3 coats of color and 2 coats of clear on my restorations. Some colors need more coats (or less), especially metallics, to get the shade you want. More coats will obviously make a darker finish.

[bobh]

I agree with Leon with 3 light coats. I've also started using Spray Max clear coat gloss on them. Gets real nice flow from it and holds up.

[tjthechainsawmech]

3 coats is about right, I've always been one to stack coats.....especially clear. Makes for a deeper finish.

[Deleted]

Aug 4, 2017 15:03:13 GMT -5 strtjoints said:

How many coats of orange red engine pain is normal for repainting, I have primed it as well . All paint is dupli color. Im restoring my 719. Also I have engine clear coat . how many coats of each do y'all think? Thanks

I'm not sure I would use a primer on magnesium unless it was an aircraft type yellow chromate etching primer. Primer is mostly for metals that have high levels of oxides or react when oxygen gets in them. Iron oxide or rust is formed when iron and oxygen react in the presence of water or moisture in the air. So to prevent this we use a primer that stops the process through a special red oxide primer that absorbs any water before it gets to the metal. However magnesium being a non ferrous metal does not rust it corrodes, so the primer used if any should address the chemical makeup of the metal. Prior to any primer or painting magnesium needs to be degreased and pre-treated by deoxidizing and priming prior to painting; that will clean it. Since magnesium is more alkali resistant than aluminum, it is degreased using strong alkaline cleaners. Deoxidizing can be done by acid pickling with chromic acid. Blast cleaning will also remove oxidation. However it must be done carefully so that oily residues and corrosion-causing contaminants are not driven into the magnesium surface. Back to the primer, an aviation type Zinc Chromate primer is a good choice, but in lieu of, or beside a primer, pre treatments of magnesium are recommended and may present more complications for the average person. This is why I would use a high solids aliphatic polyurethane epoxy paint or clear coat and not primer. In order to correctly prep magnesium for painting it can require several steps and with several different types of treatments.The pretreatments for magnesium are: Type I Chrome-Pickle treatment, Type II Sealed Chrome-Pickle treatment, Type III Dichromate treatment, Type IV Galvanic Anodizing treatment, Acid Chromate Anodic process. Many of these pretreatments involve multiple stages, which is probably the reason people say magnesium may be difficult to paint. Primers for magnesium generally contain zinc chromate pigment. Certain zinc chromate primers are actually pretreatments and should be applied directly to bare, cleaned magnesium and not be applied over other pretreatments. After priming, most paint finish systems can be used for painting magnesium and even if you do not opt for a High Aliphatic polyurethane paint, you should use a aliphatic polyurethane clear coat over the top of any paint not designed to withstand contact with solvents. Do not use a heavy coat or coats of the clear, several light coats is the proper application method.

[sweepleader]

Leon was on vacation and too busy to remember what he posted on his own site about painting so here it is. (I forgot about it too so I suppose I should cut him some slack.)

www.leonschainsawpartsandrepair.com/homelite-chainsaw-restoration.html

OK there Mr. oologahan, that is my kind of answer, zinc chromate is not often talked about regarding chainsaws. It is my go to primer for aluminum or mag, should I be wary of some pitfall with mag other than being sure it is atomically clean? How about "Certain zinc chromate primers are actually pretreatments..." how do I tell which are "certain" and which are not? How about "self etching primers" on mag?

[Deleted]

Oct 26, 2017 12:18:08 GMT -5 sweepleader said:

Leon was on vacation and too busy to remember what he posted on his own site about painting so here it is. (I forgot about it too so I suppose I should cut him some slack.)

www.leonschainsawpartsandrepair.com/homelite-chainsaw-restoration.html

OK there Mr. oologahan, that is my kind of answer, zinc chromate is not often talked about regarding chainsaws. It is my go to primer for aluminum or mag, should I be wary of some pitfall with mag other than being sure it is atomically clean? How about "Certain zinc chromate primers are actually pretreatments..." how do I tell which are "certain" and which are not? How about "self etching primers" on mag?

Some yellow chromate is actually zinc phosphate. In general zinc chromate is a more robust and effective corrosion inhibitor for steel and magnesium than zinc phosphate. Large amounts of chromates ( hexavalent chromium Cr6+) at manufacturing plants present the potential  for carcinogenic health hazard to painters so many companies prefer to use alternatives such as zinc phosphate.  When comparing aqueous zinc phosphate pretreatment with iron phosphate, the zinc phosphate is the better corrosion preventive for steel and iron, but for magnesium an aircraft grade zinc chromate is recommended for magnesium for its corrosion resistance. The problem with a "self-etching primer" is that is just a set of words used as a marketing tool. In the fine print it will detail how "your mileage may vary" depending on the application. In other words, not all self-etching primers are created equal.