automotive primer for HDU gilded letters?

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I read somewhere that automotive primer is not supposed to be used for priming HDU. It would sure make the job of getting the HDU smooth easy. Anyone know why it's not recommended? I've got letters to gild and I don't want to spend more time than I have to trying to sand latex primer.

Adrian

[Billct2]

We use auto primer on HDU. I haven't heard anything about adverse effects of using it.

[Rich]

Water based, oil based and even lacquer based paints will adhere. However, to achieve a smooth finish for your gold leafing sizing, I would recommend that you sand the letters first.

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Thanks guys. I couldn't imagine what harm lacquer primer/surfacer would do to HDU. I sand my letters to 220 grit then start priming and sanding. Do you size right over the primer or do you paint on something yellow first?

Adrian

[Rich]

Thanks guys. I couldn't imagine what harm lacquer primer/surfacer would do to HDU. I sand my letters to 220 grit then start priming and sanding. Do you size right over the primer or do you paint on something yellow first?

Adrian
Yes. Use slow size for brighter finish. Mix in a little 1-Shot Crome Yellow. Use very little, just enough so that you can see your brush strokes clearly. Give the letters an even coat of this size, brushing the size out well to avoid getting the color to thick in spots. Avoid "holidays" as the smallest bare sot will leave a bad blemish in your gild. When the size dries to a tack where you can rub your finger across it without picking up paint, it's ready for your gold leaf. The size should give a little squeaking sound when finger is pulled across it, otherwise, it's too dry.

Good Luck and Have Fun!

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Rich,

Thank you for the tips. I am definitly winging it with the gilding. I don't know anyone who can show me in person how it's done so I'm gratefull for any advice.

Adrian

[Rich]

Rich,

Thank you for the tips. I am definitly winging it with the gilding. I don't know anyone who can show me in person how it's done so I'm gratefull for any advice.

Adrian

Your Welcome.......glad I could help!

[Billct2]

Get the book on gilding available thru Signs of The Times

[3dsignco]

We use High build Automotive primer all the time onHDU works Great.. You do want to sand it down but then you also want to give it a nice glossy top coat befor you gild.

The thing about gold is it will only be as bright as what you put it over. You can sand down primer with 1000 grit and and have it baby butt smooth but the primer is still flat so your gold would have a flat look to it. (which sometimes you may want that) But if you paint it with a good gloss top coat. (We usally use 1shot Chrome yellow or a good Automotive paint depending on the job).

As for applying the gold size there is many ways of doing it. Some people will mix paint in their size so they can see it as they brush it on. What I do now since I only have about 2 quarts left of the old LeFranc lead size is we started using the Rolco size and I reduce about 15 to 20% with real turps and then spray a very light coat Almost a mist just so it covers and levels out on my letters then wait till the required amount till you have your squeek. Here in Colorado our wait time is a little less then humid areas. Usally around 24 hour or so. Then guild. You will have a very bright almost mirrored finish on your gold.

This technique is a spin off from I learned from Cam Bortz on the way he does his lettering as he wipes off most of the size on his lettering.

The huge ordeal in gold is not to gild too early.
As biilct2 said get Kent Smiths revised edition of Lefrancs book "Gold Leaf Tecniques" or look around on Ebay and you may find the original LeFranc book.
I am by no way a master gilder yet but this is what works for us.

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Thank you Bill. I would like to try spraying the size. All I have is one shot fast dry size. Does the size you use get a really thick skin on it in the can? I find it to be pretty weird stuff as varnish goes.
I thought I would look into getting a more traditional slow size. My gilding is a bit dull for my taste but it still looks nice enough. Still, it would be nice to get it mirror bright.

Adrian

[3dsignco]

Yea I always get the film on the 1 shot. As for the others No film.
You can use the 1shot the same way just that you don't have a very long open time.(At least here we don't. I always run into problems with the 1 shot setting up too quick on large projects so I just limit it to small pieces and for matt gold on glass

[imaSIGNr]

For HDU I would suggest using high build primer( chromatic brand for hdu ) or Jay Cooks primer. HDU is so porous that anything else will not seal it without many coats. IMO. Then you can light sand , must be dust free, size and gild. I would not spray size though. If you brush it, it will lay down smooth. You must use very sparingly or it will run/sag. Add a few drops of chrome yellow 1-shot so you can see where you've been. Let dry. Test size by dragging back of knuckle on sized area. You should get a squeaky sound . It my appear to be dry. The closer it is to this almost dry point, the higher gloss you will have in your gild....Don't get too far ahead of your gild time. If you have a lot of area, be patient and do a few at a time and space out your sizing time, cause you can size faster than you can gild....You can buy slow or fast size also. You can buy different brands. I like the LaFranc brand ( French )

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Bill,

I found it takes about 2 hours for the 1 shot to setup to what I think is set up.
I squirt argon/co2 from my mig welder into the can before I put the lid on. It reduces the skin. Once, I opened the can and there was no skin at all...It does help.

Imasignr...I found 2 coats of auto high build laquer primer filled the HDU completely and it sands so easily between coats. I've only used it once - on the letters for the sandblasted sign I did - so I will have to try it a few more times before I can recommend it with any conviction.
I lay the size on very thick so it will flow out. I have to watch for runs but I don't have much trouble with them. I goes to show..I really don't know what I'm doing...all trial and error. I would like a brighter finish though.
Does slow size give a longer gilding "window" verses fast size? I do the gilding in stages so I don't have a lot a size on at a time. If I had a longer "open" time it would save time, I think.

Adrian