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Conformal Coating that doesn't require fancy equipment...

Steve Gregory

#14880

Conformal Coating that doesn't require fancy equipment... | 23 July, 1998

Hey youse guyz... We're finally getting our first real job at the start-up I'm working at. It's actually a pretty unique little board too. Simple as all get out, but unique. You're not gonna believe what this goes into...guess? (I bet ya' you'll never guess it) Give up? A toilet seat! You read it right, a toilet seat! It's actually a little controller board for a system that automatically covers the seat with a plastic tube type of cover when people get up from the seat from doing their thing...pretty cool huh? Sure beats those paper "butt-gaskets"!! There's some systems installed in the womens restroom at O'Hare airport in Chicago, and they've got them in the womens restrooms at some casinos out here in California. Anyways, we're gonna be doing the assembly for these puppies, and because of the chemicals that they use to clean restrooms (not to mention the "green-fog" that sometimes comes outta people...hehehe), the board needs to be conformal coated. On the units that have been built so far, it looked like they used some sorta RTV or silicone material on them, it looks pretty ugly. Since I don't have much experience with conformal coating at all, could anybody recommend a coating that the boards can basically just be dipped into and not require a bunch of equipment, or a enclosed work station to do this with? I've got a email in to Humiseal to see if they can recommend one of their products, but I thought I'd ask the REAL experts about this...yes, that means YOU! Thanks pardners!!! -Steve Gregory-

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Wayne

#14886

Re: Conformal Coating that doesn't require fancy equipment... | 24 July, 1998

| Hey youse guyz... | We're finally getting our first real job at the start-up I'm working at. It's actually a pretty unique little board too. Simple as all get out, but unique. You're not gonna believe what this goes into...guess? (I bet ya' you'll never guess it) | Give up? A toilet seat! You read it right, a toilet seat! It's actually a little controller board for a system that automatically covers the seat with a plastic tube type of cover when people get up from the seat from doing their thing...pretty cool huh? Sure beats those paper "butt-gaskets"!! There's some systems installed in the womens restroom at O'Hare airport in Chicago, and they've got them in the womens restrooms at some casinos out here in California. | Anyways, we're gonna be doing the assembly for these puppies, and because of the chemicals that they use to clean restrooms (not to mention the "green-fog" that sometimes comes outta people...hehehe), the board needs to be conformal coated. On the units that have been built so far, it looked like they used some sorta RTV or silicone material on them, it looks pretty ugly. Since I don't have much experience with conformal coating at all, could anybody recommend a coating that the boards can basically just be dipped into and not require a bunch of equipment, or a enclosed work station to do this with? I've got a email in to Humiseal to see if they can recommend one of their products, but I thought I'd ask the REAL experts about this...yes, that means YOU! | Thanks pardners!!! | -Steve Gregory- Steve: Great PIC! WOW As for conformal coating there are a few good ones that might be just right for you, I would recomend you look into using something like Parylene (normally used for hi-rel and harsh invironments) This sounds pretty harsh to me...hehe Not sure how your are handling the application but you might want to look into controlled spray applications that do not require masking and I suggest that you look at SCS Specialty Coating Systems. They are owned by Cookson and have an a nice conformal coating system. Also a curing oven that goes with the selective spraying system and can be placed in line with your SMT line. You can reach them at (800) 356-8260 (gee I like those free phone calls) I have attached their website for you to go and look. They provide a conformal coating service that might be interesting to you if the volumes are too low to justify purchasing of the equipment. Don't forget to flush! Wayne

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Dave F

#14884

Re: Conformal Coating that doesn't require fancy equipment... | 24 July, 1998

| Hey youse guyz... | We're finally getting our first real job at the start-up I'm working at. It's actually a pretty unique little board too. Simple as all get out, but unique. You're not gonna believe what this goes into...guess? (I bet ya' you'll never guess it) | Give up? A toilet seat! You read it right, a toilet seat! It's actually a little controller board for a system that automatically covers the seat with a plastic tube type of cover when people get up from the seat from doing their thing...pretty cool huh? Sure beats those paper "butt-gaskets"!! There's some systems installed in the womens restroom at O'Hare airport in Chicago, and they've got them in the womens restrooms at some casinos out here in California. | Anyways, we're gonna be doing the assembly for these puppies, and because of the chemicals that they use to clean restrooms (not to mention the "green-fog" that sometimes comes outta people...hehehe), the board needs to be conformal coated. On the units that have been built so far, it looked like they used some sorta RTV or silicone material on them, it looks pretty ugly. Since I don't have much experience with conformal coating at all, could anybody recommend a coating that the boards can basically just be dipped into and not require a bunch of equipment, or a enclosed work station to do this with? I've got a email in to Humiseal to see if they can recommend one of their products, but I thought I'd ask the REAL experts about this...yes, that means YOU! | Thanks pardners!!! | -Steve Gregory- Steve: There are a lot of $50k dedicated sprayers and $15k X-Y tables with spray heads attached out there. You can even buy spray guns like they use over at Maaco. But have I got a decidely "unfancy equipment" approach for you!!! 1 Make a drying rack. You could use knotted cord, light weight chain, or, my preference, one of those frames that some people use to dry their underwear. 2 If using cord or chain, attach the cord (chain) to walls on opposite sides of a room. 3 Put newspapers on the floor under the drying rack. 4 Unbend a paper clip once and pass one end though a mounting hole on the board. 5 Dump the coating material into a bucket with a mounth that is larger than the board. 6 Holding the paper clip, dip the board into the bucket containing the coating material. 7 Hang the board by the paper clip on the drying rack. Be consistant on: 1 Keeping the coating material thinned. 2 Using the same dipping motion on each board. Depending on the coating material, you may want to provide the person processing the boards with breathing protection. There is a company in Paterson NJ that makes a machine that does the dipping portion of this. I'll email the name, if you're interested. Good luck and I hope the facilities using your board never run out of paper. Dave F

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Mike Moninger

#14885

Re: Conformal Coating that doesn't require fancy equipment... | 25 July, 1998

| Be consistant on: | 1 Keeping the coating material thinned. | 2 Using the same dipping motion on each board. Amen on thinning the coating, and you might also be concerned about the curing mechanism for the coating. Moisture-cured and 2 component systems (e.g. polyurethane and silicone) may not be suitable for use this way without some method of keeping atmospheric moisture away. Since acrylics do not cross link and dry only by solvent evaporation, addition of thinner to control viscosity will not degrade performance. | Depending on the coating material, you may want to provide the person processing the boards with breathing protection. Change "may" to "must", and I'll agree here, too. This stuff is fumey with a capital F. A table top exhaust booth may suffice to ventilate the area for a couple of grand. And I'm biased, but application services make sense for a lot of applications. If you can dip without masking, though, you can do it cheap. Mike Moninger Thermospray Company, Inc.

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Chris Fontaine

#14883

Re: Conformal Coating that doesn't require fancy equipment... | 27 July, 1998

Steve, We do a lot of hand spray conformal coating and have had much success. We have had much experience with Humiseal 1A20 Urethane. Acrylics are easier to work with but may not stand up to your environment. I don't have any experience with silicone CC, but silicones in general tend to contaminate everything they touch. I'd recommend spraying the urethane with either a spray gun or air brush, and ventilation and breathing protection are a must. The advantage to using the 1A20 is that it's a one part CC, and cures by moisture absorption in about 24 hours (at 50% RH), so there's no need for curing or UV ovens. Just make sure that you test before you coat because rework can be somewhat difficult. Chris Fontaine Manufacturing Engineer Sanders, a Lockheed Martin Co.

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Brian Stumm

#14881

Re: Conformal Coating that doesn't require fancy equipment... | 28 July, 1998

Steve, I know it is tempting to go for the cheapest method of applying conformal coatings but I must warn you. If you are a contract manufacturer then you don't want to limit yourself in the types of coatings you can work with. Just as soon as you set up some cheap system of dip coating someone will want selective coatings. Or if you set up to handle acrylics you'll sure to be asked to use silicone. I also noticed someone suggest a coating that does not require a cure oven because it is moisture cured. Two problems there, finding a place to put all the boards while they dry and what happens on days when the relative humidity is less than 50%? Of course the RH will probably be over 50% every day but the day you are trying to meet a deadline. I suggest you purchase a flexible system that will handle all coating types. It may cost more now but will probably save you money in the long run (not to mention preventing you from turning down orders, none of us want to do that). If you need any help with the oven department let me know. My company is the manufacturer of Nordson's ovens (picture above) and I have a new and used ovens to offer you at factory direct pricing (like I said, were the manufacturer). If you need additional info contact me. Sincerely, Brian Stumm ETS, LLC 509-483-0900 (voice) 509-483-0331 (fax) ets@eznet.com (e-mail) | Hey youse guyz... | We're finally getting our first real job at the start-up I'm working at. It's actually a pretty unique little board too. Simple as all get out, but unique. You're not gonna believe what this goes into...guess? (I bet ya' you'll never guess it) | Give up? A toilet seat! You read it right, a toilet seat! It's actually a little controller board for a system that automatically covers the seat with a plastic tube type of cover when people get up from the seat from doing their thing...pretty cool huh? Sure beats those paper "butt-gaskets"!! There's some systems installed in the womens restroom at O'Hare airport in Chicago, and they've got them in the womens restrooms at some casinos out here in California. | Anyways, we're gonna be doing the assembly for these puppies, and because of the chemicals that they use to clean restrooms (not to mention the "green-fog" that sometimes comes outta people...hehehe), the board needs to be conformal coated. On the units that have been built so far, it looked like they used some sorta RTV or silicone material on them, it looks pretty ugly. Since I don't have much experience with conformal coating at all, could anybody recommend a coating that the boards can basically just be dipped into and not require a bunch of equipment, or a enclosed work station to do this with? I've got a email in to Humiseal to see if they can recommend one of their products, but I thought I'd ask the REAL experts about this...yes, that means YOU! | Thanks pardners!!! | -Steve Gregory-

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Brian Stumm

#14882

Photo version: Conformal Coating that doesn't require fancy equipment | 28 July, 1998

| Steve, | I know it is tempting to go for the cheapest method of applying conformal coatings but I must warn you. If you are a contract manufacturer then you don't want to limit yourself in the types of coatings you can work with. Just as soon as you set up some cheap system of dip coating someone will want selective coatings. Or if you set up to handle acrylics you'll sure to be asked to use silicone. I also noticed someone suggest a coating that does not require a cure oven because it is moisture cured. Two problems there, finding a place to put all the boards while they dry and what happens on days when the relative humidity is less than 50%? Of course the RH will probably be over 50% every day but the day you are trying to meet a deadline. | I suggest you purchase a flexible system that will handle all coating types. It may cost more now but will probably save you money in the long run (not to mention preventing you from turning down orders, none of us want to do that). | If you need any help with the oven department let me know. My company is the manufacturer of Nordson's ovens (picture above) and I have a new and used ovens to offer you at factory direct pricing (like I said, were the manufacturer). | If you need additional info contact me. | Sincerely, | Brian Stumm | ETS, LLC | 509-483-0900 (voice) | 509-483-0331 (fax) | ets@eznet.com (e-mail)

| | Hey youse guyz... | | We're finally getting our first real job at the start-up I'm working at. It's actually a pretty unique little board too. Simple as all get out, but unique. You're not gonna believe what this goes into...guess? (I bet ya' you'll never guess it) | | Give up? A toilet seat! You read it right, a toilet seat! It's actually a little controller board for a system that automatically covers the seat with a plastic tube type of cover when people get up from the seat from doing their thing...pretty cool huh? Sure beats those paper "butt-gaskets"!! There's some systems installed in the womens restroom at O'Hare airport in Chicago, and they've got them in the womens restrooms at some casinos out here in California. | | Anyways, we're gonna be doing the assembly for these puppies, and because of the chemicals that they use to clean restrooms (not to mention the "green-fog" that sometimes comes outta people...hehehe), the board needs to be conformal coated. On the units that have been built so far, it looked like they used some sorta RTV or silicone material on them, it looks pretty ugly. Since I don't have much experience with conformal coating at all, could anybody recommend a coating that the boards can basically just be dipped into and not require a bunch of equipment, or a enclosed work station to do this with? I've got a email in to Humiseal to see if they can recommend one of their products, but I thought I'd ask the REAL experts about this...yes, that means YOU! | | Thanks pardners!!! | | -Steve Gregory-

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Samuel F.

#14887

Re: Conformal Coating that doesn't require fancy equipment... | 10 June, 1999

Humiseal probably won't work as most of them are solvent based or require pretty high temp cures. MicroCoat technologies manufacturers UV cure epoxy conformal coating materials that have been used to coat just about anythin (except the green fog) Call me at 203-271-3035. I'll send data sheets and MSDS or E-mail me at ucoat1@aol.com

Sam Forman

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