Easy Plaque Patterns

I have detailed this before, But it deserves a revisit

Easy Plaque Patterns
1) I order a customRubber stamp from
http://www.villageimpressions.com/index.htm
as long as you say "foundry pattern" they know exactly what you want, ( rubber stamps are normally reversed) they can work with any art, but monocolor, just one shade of black one, shade of white is best, this is the same technique as old school wood cuts which used to be used to ilistrate books, so there is alot you can do, Villiage impressions can handle pieces up to about 10X10 inches. contact them, they are awesome


once you have your stamp in hand, the back will be about 3/32 thick (2.4mm) , that is really thin for a foundry pattern, so you want to thicken it up, (there is a balancing act here, thicker plaques POP , but at $6/Lb, brass or bronze gets expensive ) but you got to thicken it up some just to Make minimum casting thickness. I used to use Hobby Plywood 3/32, but it was pricey too, or you can get 1/8 MDF ,I did not like rough back amd the odd dust, so I tok to gluing together paperboard it's about 1/32 per sheet so stack it up, I went 5 thick for some extra OMPH . in this instance a pair of cutup raisen bran boxes, cut them oversized to add draft the best way to glue them is with contact cement ( you have that for your disk sander )

now we are all glued up , you need a fresh 120 grit wheel or belt or drum on your sander , roll your table back 5° and put on your draft. (the fresh sand paper is important to cut the rubber clean)

though it does not absolutely require it, these projects really work best as a matchplate, I always lay mine out with the entire gating system, if you are only going to use the pattern once or twice, go easy when you glue down the pattern with PVA glue, just get the edges good and a spot in the middle, you can get the pattern up and reuse the matchplate for something else later,

her is our finished patterncoated with rattle can automotive primer steel wooled with 000 and graphite powder, that is the black , helps the pattern release (makes it slippery Graphite is a dry lubricant. note I use fillet wax around the entire perimeter of the pattern and gating system to make sure no sand gets under the pattern and hangs... dont skip this order a role of 00R fillet wax from Freeman pattern supply, their smallest fillet iron, you can use any alcohol lamp, but freeman sels nice metal ones
https://www.freemansupply.com/products/specialty-tooling-waxes/wax-fillets-accessories


here is the mold , absolutely perfect first time, little note, I seldom use these more then a couple times, so if you need to make alot of pieces, cast your first one out of aluminum for a master pattern, and set it aside, use the rubber patern for as long as you need or can, but haveing that aluminum (or Zamak) backup is a great feeling of safety.

here is our casting hot out of the sand(literally still smoking) thats Petrobond sand , this piece was 60/40 Yellow brass mostly from scrap, any Brass or bronze would have been fine for this , I poured Brass at 1096°c, the tin bronzes would have needed 1260°c, so Brass saves some fuel

and of course the finished piece polished, antiqued and mounted on a hand rubbed and polyurethaned 8X10 inch cherry back , since this was a givt I used JAX antique brown for the antiquing , and then rubbed it with Johnson paste wax for protection,
for comercial pieces, I antique with Brown rattle can spray paint, and knock off the highlights with laquer thinner and a rag , Much easier and cheaper


This Piece was done for the fools with tool treasure trade , you can check out the podcast
https://fwtpodcast.com/
they have a great group on facebook lots of nice people all interested in making some great art


Hope this helps someone out

V/r HT1

P.S. this would be the easiest way ever to make custom font alphabets in any size

 

HT1, maybe put the Village Impressions info in the Links to Useful Info section for future reference?

How does the fillet wax hold up to packing sand? I know use use petrobond and I think you pack less hard than with green sand. I tried some quite a while ago but seemed to have trouble with sand embedding in the wax.

Denis

I just went to their web page and founsd the following pricing info for those, like me, curious:


What Does it Cost?


Here are some typical prices to give you an idea of the cost, but I will always provide you with a firm total cost before you place your order.

Single Stamps

I am happy to make just one stamp if that is what you need. I have no set up fees, no minimum orders, no design fees, there are no hidden charges of any kind. I sell a lot of small single stamps, no order is too small.

Single Small Stamp

(2” x 2”)

$ 18.00

Single Medium Stamp

(3” x 3”)

$ 23.00

Single Large Stamp

(4 ”x 4”)

$ 30.00

Single stamps are priced by the square inch

Full Sheet

(8” x 10”)

$ 75.00

Quarter Sheet

(4” x 5”)

$ 35.00

Half Sheet

(8” x 5”)

$ 53.00

Best buy is a full sheet—fit on as many stamps as you can cut out

Sheets of Stamps

I offer reduced prices for full, half and quarter sheets. Fit as many stamp designs into the area as you can, just leave room to cut them out.

The lowest cost per stamp will be a full sheet, why not get some friends together to fill up a sheet if you only need a few designs of your own.

Sheet stamps are sold un mounted and un trimmed, so you have the fun of cutting them out! Any scissors will work but I like to use Teflon coated long blade scissors. They glide through the stickiness of the stamps with ease and allow for smooth curvy cuts around your stamp design.


Village Impressions


main e-mail: stamps@villageimpressions.com


PO Box 610989 - Port Huron - Michigan - 48061 - 0989 - USA

PO Box Twin Lakes - Sarnia - Ontario - N7S 6J4 - CANADA

 

FWIW, Village Impressions is run by the wife of one of our members, JoeC, aka Foundry Joe on the AA forums.

 

as long as you seal it perfectly ... OK dont go nuts with the wax fillets , they go up to like 3/8 radius , at that point you should have moved to leather fillets, Long ago,

I use 00R and 1r thats it , 1r is smaller then a toothpick in diameter .

fillets this small really are to make sure sand cannot get under the pattern, and to fill gaps in the gating sytem, or to repair backdraft,
remember iron your fillets down, then scrap any excess, then give the pattern a coat of your favorite sealer, mine is autobody primer , then carefully steel wool all the fillets 00 or 000, this will catch an stray wax if your happy coat it again, then sprinkle it with dry graphite, then steel wool that til the surface of the pattern has a nice slick blackish appearance, if you see problems with your fillets at this point, clean steel wool the offending area, touch up your fillets, then quick seal (if it is really small, you can just steel wool with graphite ,

the graphite powder is important, i gently rub my patterns with a graphite bag (Link below) between each ram ... on great patterns you can do every other
I have one for graphite and one for parting compound
if you do this, and get sand entrapped in your wax, you are ramming WAY TOO HARD


https://www.uline.com/Product/Detai...lQ85MDOV1cbe5PAEY2xoC1vQQAvD_BwE&gclsrc=aw.ds


V/r HT1

 

I have used graphite on my patterns for some time. In the past I have simply used a soft brush to apply it and it did help improve clean drawing. However, after reading HT1's recommendation to scub it onto a pattern, I used a shop towel to scrub the graphite onto the pattern. Scrubbing it on did improve the graphite coating noticably. Good tip.

Denis

 

one more grapite tip:
get a parts cleaning brush trim the bristles back about half, use this to work graphite into small details, like the interior of letter, you have to avoid being rough around wax fillets with this, but for heavy details, and the dreaded centers of :RDAQOP nothing gets the graphite in there better



V/r HT1

 

I use one of my wife's old powder brushes. Very soft and gets in small areas.

 

if that is working for you great! but i found a soft brush just did not "work " the graphite onto the surface of the pattern, it just moved it around on the pattern . my goal is to do just what a pencil does, work the graphite into the paper, so a hard brush is superior, same result as rubbing with the parting bag, the brush just gets into smaller areas better, but is actually too agressive to use everywhere .

now remember i apply graphite to the pattern to make it slick , then apply parting , the graphite stays on the pattern for the most part, the parting stays on the mold, so your parting has to be a smoothe even layer, I cringe when i see guys squirting talc out of the bottle , that will leave clumps of parting, which will affect surface finish very negatively . I sprinkle parting dust very high above the pattern, and let a fine layer settle down on the pattern

now most of my work is plaques, so the surface appearance is about my onlyn concern, if I was making parts to be machined, I would just shake some parting on and start ramming

V/r HT1

 

With respect to parting compound, it is usually just talc with maybe some additive to make it “proprietary.” When I can get it, I buy “ shower powder” at the local DealsOnly store. Very cheap and the perfume they add is not too annoying. Otherwise, the best deal seems to be available on Amazon as Teton-Part. 2 pounds at 18 dollars delivered. Other than the perfume in the shower powder, I can’t tell a difference in appearance, feel, or performance.

https://www.amazon.com/Teton-Part-F...keywords=Parting+powder&qid=1603542237&sr=8-1

If there is a better deal, I’d be interested.

I found out the hard way that visible talc clumps on a pattern cause rough surface areas. This must be due to heat causing the talc, a form of Mg silicate to break down and off-gas. So, using a moderately fine mesh bag, I apply the talc generously to the pattern or packed mold with embedded pattern and brush it all around on the sand and pattern with a soft brush. Then I carefully blow off any visible accumulations of talc on the pattern using compressed air or one of those handy rubber bulbs. Even though you can’t really see the talc on the pattern, you can feel it and it still makes the sand slip off cleanly.

Denis

 

diatomaceous earth pool filter media. $25 for 50lb box. Move it to a couple of buckets lasts for years

can get it at the home center

in the good old days parting was powdered silica... OSHA would loose their minds if anyone tried to market that now. It cost same as sand. Probably because it was a byproduct out of the dust collection at the sand processer

b
V/r HT1

 

Talc is still available although I'm not sure they still make baby powder out of it. Next time you're in the GTA, you can pick up lifetime supply in Oakville, $32 for 50lbs, https://psh.ca/collections/talc-texas-amtal-c-98/products/50-lbs-texas-talc-texas-amtal-c-98. BTW, that place has quite a few things of interest to the home founder, it's where I got my bentonite and sodium silicate.
Here's another even cheaper and possibly less hazardous option for parting powder, it is the primary component of Smelko's white parting agent: https://psh.ca/collections/calcium-carbonate-whiting/products/50lbs-calcium-carb-whiting.

 

I have parting powder, which is not talc but it didn't always work well with petrobond.

One day I tried dry sand as a parting medium and it works very well. This is also mentioned in Ammen's book,

Cheers Charlie

 

So, following your clue, I found talc listed very cheaply at various pottery supply places. That is where I’ll get my next batch. Works great with green sand.
Thx!
Denis

 

that research is pretty easy, they checked the SDS, formerly MSDS, quite often on very common stuff it lists the ingredients, and persentages, if you buy chalk line dust by the gallon, it is very cheap ,

But in petrobond you guys have seen my results with Graphite and DE on brass and Aluminum, so I cannot see any reason I would change.

V/r HT1