Can someone help me with this paint math?

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DiverJosh82
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Can someone help me with this paint math?

Post by DiverJosh82 » 10 Sep 2016, 09:23

Hello all,
So I am going to be applying a coat of Rustoleums bare metal primer on to a thin layer of their self etching paint today but I need some help.. I am going to be spraying it on and I have a math question. I think I am going to thin it a tiny bit to help it flow through the gun a bit better. Now on the can it says to thin no more than 5% by volume with mineral spirits but I am terrible with math and can't figure that out lol. First can I just thin it in the rusto can and will it be ok if I don't use it all? And if I do it in a separate container I probably will do small batches of 10oz or less. So if I do 10oz whats 5% of that? 10x.05 is .5. so do I use half an ounce or thinner? Sorry for such a trivial dumb question..
Josh

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Johnny
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Can someone help me with this paint math?

Post by Johnny » 10 Sep 2016, 09:39

LOL not trivial at all !!!

ok - you more or less answered your own question.
if you are using a 10oz cup, 10% would be one ounce of thinner per cup.
5% would be half that at 1/2oz of thinner per cup, yada yada yada

your location, humidity, temperature, etc, dictates what kind of thinner
and how much to use. Just because the manufacturer suggests 5% thinner,
your conditions may need less or more to work well. Plus other paint modifiers
could be used. Regular Mineral Spirits is a nice medium, slow evaporating thinner.
(Don't use the artist's "odor free" type - that is for girls).
PHOTOS of your project would be great !!
paint.png
paint.png (6.47 KiB) Viewed 628 times
and my math skills give me FITS every day !!!




.
Last edited by Johnny on 10 Sep 2016, 10:05, edited 2 times in total.
http://www.tinboats.net/how-to-build-a-transom/
http://www.tinboats.net/varnish-vs-polyurethane/
All about Primers = http://www.tinboats.net/primer-and-paint-basics/
Paint, Thinners and Applications = http://www.paintingforpainters.com/

1959 Crestliner Commodore 14'
1959 Lone Star Malibu 14'
1958 Johnson 35 RDE-19 Sea Horse
1958 Johnson 35 RDS-20 Super Sea Horse

oldude
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Can someone help me with this paint math?

Post by oldude » 10 Sep 2016, 09:43

You are correct. I/2 oz of thinner for 10 oz paint.

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DiverJosh82
Posts: 29
Joined: 31 Jul 2016, 16:15

Can someone help me with this paint math?

Post by DiverJosh82 » 11 Sep 2016, 07:57

Johnny wrote:LOL not trivial at all !!!

ok - you more or less answered your own question.
if you are using a 10oz cup, 10% would be one ounce of thinner per cup.
5% would be half that at 1/2oz of thinner per cup, yada yada yada

your location, humidity, temperature, etc, dictates what kind of thinner
and how much to use. Just because the manufacturer suggests 5% thinner,
your conditions may need less or more to work well. Plus other paint modifiers
could be used. Regular Mineral Spirits is a nice medium, slow evaporating thinner.
(Don't use the artist's "odor free" type - that is for girls).
PHOTOS of your project would be great !!
paint.png
and my math skills give me FITS every day !!!




.
Thanks for the help. I was hoping you'd chime in. I've seen some of your responses in the past and you seem pretty knowledgeable. Do you have any knowledge on the "old timers formula"? I bought the stuff to do it yesterday and was thinking probably so the hidden backside of the transom first, but do you have to rub it in at all so the linseed oil portion can penetrate the wood? Or just roll or brush it on..

lckstckn2smknbrls
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Joined: 05 Oct 2008, 12:14
Location: Algonquin Il

Can someone help me with this paint math?

Post by lckstckn2smknbrls » 11 Sep 2016, 08:40

You apply the OTF until no more will soak into the wood and it pools on the wood. Then you wipe off the excess and let it dry for 72 hours or more. Then apply one or two coats of straight Spar.
1971 14' Ward's Sea King Jon Boat / 1983 Mariner 25HP

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DiverJosh82
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Can someone help me with this paint math?

Post by DiverJosh82 » 11 Sep 2016, 08:42

lckstckn2smknbrls wrote:You apply the OTF until no more will soak into the wood and it pools on the wood. Then you wipe off the excess and let it dry for 72 hours or more. Then apply one or two coats of straight Spar.
Thank you kind sir. Should I do the back and then let it dry before flipping it over to do the visible side? Or just flip it on some blocks and not care what the back looks like?

lckstckn2smknbrls
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Joined: 05 Oct 2008, 12:14
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Can someone help me with this paint math?

Post by lckstckn2smknbrls » 11 Sep 2016, 08:49

I worked over a plastic drop cloth and did both sides and edges at one time. Then stood my transom up on the bottom edge on 2 blocks made from 1x2's. It can and will get messy I wore rubber gloves.
1971 14' Ward's Sea King Jon Boat / 1983 Mariner 25HP

lckstckn2smknbrls
Posts: 4253
Joined: 05 Oct 2008, 12:14
Location: Algonquin Il

Can someone help me with this paint math?

Post by lckstckn2smknbrls » 11 Sep 2016, 08:52

To do my transom which is about 16" tall, 60" wide and 1.5" thick. 2 layers of 3/4" BCX plywood. I mixed up a quart and had some left over.
Each part of the formula was 8 ounces.
1971 14' Ward's Sea King Jon Boat / 1983 Mariner 25HP

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Johnny
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Can someone help me with this paint math?

Post by Johnny » 11 Sep 2016, 11:02

as described above - the secret is to LET IT DRY - LET IT DRY - LET IT DRY
before putting any more paint or varnish on it.
The ingredients do not "cure" the longer they sit, like epoxy and other two-part resins.
It cures by the evaporation of the solvents in the ingredients. It may appear to be
"dry to the touch" - but the solvents could still be partially liquid inside the wood.
What I do for a two sided object is to paint both sides and all edges and support
it firmly to dry - - - changing out the resting foot frequently so that space will dry evenly.
or, you could drive 3 or 4 16d (3") nails on each side for legs - - - paint the top and edges,
flip it over, paint the back and the edges again - - - - let it dry for as long as it takes.
or, if your horizontal space is not available, hang it from a wire from your rafters or step ladder.

This website may be a little overwhelming, but, worth the 2 seconds it takes
to "bookmark it" so you can come back again and again for different issues you may have.
http://www.paintingforpainters.com
the red information bars on the left side of the screen should help with any of your concerns

it has not been mentioned - but - this Old Timer's Formula is for raw wood or raw plywood only.
Also, the varnish or polyurethane MUST BE solvent based - not a water based product.
NOT to be used on MDO - which is an exterior sign grade plywood made specifially for exterior
applications.... MDO is precise in its dimensions and has brown craft paper on both sides and
sealed with very exterior grade adhesives. So if you need a 3/4" or 1/2" or 1" dimension,
it will give you that. Laminate sheets together with epoxies to achieve the desired thickness.
and no, I have not used this "old timer's formula"...... I have only heard of it over the years.
being a sign maker, I always have 1/2" and 3/4" sheets of MDO laying around.
I laminate 3 sheets of 1/2" together and when that cures, I laminate a sheet of
1/8" aluminum plate to the inside and fabricate the outside transom board out of
1/2" MDO with a sheet of aluminum on that too . . . .
the reason for the overkill is that I often run motors much bigger than the boat specifies.

MDO (Medium Density Overlay) is not available everywhere - it is a "search until you find it" type of product.
My Home Depot carries it.

The internet is an invaluable tool for research - but - it is only as accurate
as the knowledge and experience of the person that posted it . . . . so read and apply with common sense.

If you have a really nice boat and want the strongest lightweight transom available, on a budget,
use 1-1/4" square tube cut to the size you need ...... pop rivet a sheet of aluminum plate to that.
then, clean, prime and paint it - - - - then, bolt it to your transom, sealing the bolts accordingly.
This will probbly last longer than the boat itself.




.
http://www.tinboats.net/how-to-build-a-transom/
http://www.tinboats.net/varnish-vs-polyurethane/
All about Primers = http://www.tinboats.net/primer-and-paint-basics/
Paint, Thinners and Applications = http://www.paintingforpainters.com/

1959 Crestliner Commodore 14'
1959 Lone Star Malibu 14'
1958 Johnson 35 RDE-19 Sea Horse
1958 Johnson 35 RDS-20 Super Sea Horse

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