Rare, but possible. In general epoxy paints are milder in terms of problems. The reducing agent/thinning agent is normally nasty, but again not that bad all in all. Epoxy hardens due to a chemical reaction between the two parts, where as most otehr paints harden by the depositing of solids as the solution evaporates (simple explanation). Imron and other isocyanide type of paints, as well as 2 part linear polyuretanes work by a combination of a hardening agent to create the bonding chains, and then a evaporative agent to deposit them.
This is one reason that paints "lay" well. Normal paints like Krylon and otehr house paints are a low solids paint. The actual solid (paint particle) size is large, so lots of evaporative carrier is used to carry the solids. The paint flows well, but only as well as the carrier can. The particle size is large so the flow properties are not as high. There are other reasons as well...but this is a simple reason. The carrier is fairly mild and in most cases a simple respirator (dual cartridge with vapor filter) will be ok along with appropriate clothing. For spray apps you want to cover up more, but in general it is good to limit and minimize exposure. The curing occurs as the particles bond to each other as the carrier evaporates. It is generally a mechanical bond so the paint is not as "hard" as other types. Epoxy paints are carried by a similar process, but the particle size is normally smaller. The evaporative chemical (reducer) is similar to other paints. The paint itself cures by chemical reaction, just like epoxy. It flows moderately well due to the characeristics, but as with epoxy it is heat sensitive and flows less and less as it cures. It forms a very good bond though as the bond is chemical, not just mechanical. Again a good respirator (full face) and clothing for roll/brush and a full suit face respirator for spray is needed. Some people have allergic reactions to this type of paint, so it is necessary for them to cover 100% of their body. I suspect the Pitts guy had that allergic reaction. Imron type of paints, along with 2 part LPUs cure by chemical and mechanical bonds. The particle size is extremely small, and flows really well. The reducer is combined with a small amount of Isocyanide harder and mixed to the pigment for Imron/PPG/Acrylic Enamels, and LPUS are a 2 part harder/pigment as well. Extremely small/thin layer, great coverage, etc. DANGEROUS. This stuff is soo small and the reducer is REALLY bad because it takes the isocyanide with it as it evaporates. So you get a bad vapor that is not filtered by any mask. Can be absorbed by the skin, etc. You /can/will die if exposed directly, and many get very sick just handling the stuff. Sanding, etc can create noxious gas as well! Fresh air respirator is minumum protection. Positive pressure suit is reccomended. In some states it is illegal even to buy it if you are not a shop with the right EPA certified filters. Single part LPUs are developled for marine industry and are fairly safe. Spray is bad of course, but brushing is ok. Not very heavy, but good coverage and good results. Not quite as good as 2 part, but still really good. Generally air cured, but again a chemical and mechanical bond so it is fairly tough. Spray requires a full suit and respirator. Jason Werner ----- Original Message ----- From: "Jack Womack" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]>; "Del Schier K1UHF FN31" <[EMAIL PROTECTED]> Cc: <[EMAIL PROTECTED]> Sent: Thursday, November 21, 2002 11:23 PM Subject: Re: [RCSE] Spray paint question > I knew a man that painted a Pitts Special with epoxy > and died. He had a good respirator, but the chemicals > were absorbed through the surface of his eyes...let's > be careful out there! > RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off.
