tips for applying pattern coat

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tips for applying pattern coat

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67redrocket	67redrocket posted 10 Years Ago HOT Topic Details
Group: Forum Members Posts: 49, Visits: 486	I am going to apply pattern coat to my first mdf pattern today. Any tips? My spray gun has not arrived yet so i Will apply With brush. what is The ideal room temperature for applying This coat?
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TURK	TURK posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 101, Visits: 662	Hi RedRocket, I'm just going through that very procedure myself. MDF plugs and Pattern-Coat Primer. My workshop temps are at 24° but I think you could get away with 20° I can't imagine applying Pattern-Coat Primer with a spraygun however, I guess the size and dimensions of your plug would dictate that. As mine are quite small 150mm sqr my working quantities are only 120g at most. What will strike you is how quickly this stuff goes off ........ I managed to between 10 and 12 minutes pot life, but it'll set abruptly as soon as it begins to set ( thicken ) stop brushing. For that reason, what will it do to a spraygun and it's fittings ? because when it sets ...... it sets real hard ! There's a step by step in pictures of my procedure in the following link > http://www.vwt4forum.co.uk/showthread.php?t=249064&page=149 I'm only making small headlight brackets for vacuum forming, but it should give you an idea what to expect. PS; Be prepared for a lot of sanding TURK
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MarkMK	MarkMK posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 338, Visits: 2K	The pattern coat that EC sells is thinned with acetone, so really no danger of going off too quickly. Spraying will deliver a much finer finish and, as it's thinned down quite a lot then using a regular hvlp gun should work okay. I use the G100 cup gun but now use the FN4 nozzle (2.4mm IIRC) and this works much better than the FN6 you might use for gelcoats As TURK says, small pieces probably wouldn't warrant spraying, but you'll find trying to flat down brush marks on bigger projects a chore and will usually break through and need further coats. I sometimes mix primer with gloss and try to build up a few coats first, so giving a bit more material to flat back and, hopefully, limit the need to keep re-applying. A foam pad on a stick, as found from some arts and crafts suppliers can also give a slight more even finish in lieue of using a brush
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MarkMK	MarkMK posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 338, Visits: 2K	18° C is probably the minimum you want but you can increase the catalyst ratio slighty to help cure times.
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