Patternmaker's letters

[Pete O]

Stage 2 went better than I had hoped.
   
   
   

Stage 3 is under way, this was the dregs of a tin of bog. Had to go into town for a new tin.
   

[Pete O]

I guess it's time for a progress report on this, although it is steeped in disappointment. I spent a lot of time casting letter blanks in body filler putty and finishing them to some sort of standard for casting. Given that i don't have anything like the proper tools for carving, I got results that I was prepared to try a pour with. I finished the rest of the pattern and glued the letters in place to spell out the two machines, my name, town and the year 2019.
Today was going to be casting day as the weather forecast was excellent, with rain throughout the rest of the week both sides. I spent about four hours experimenting with ramming the mould for the nameplate, each time getting some kind of variation on this
   

I worked on the mould each time, shaving a little more draft onto the areas that consistently hung up, until I eventually got an almost clean mould, just a few small areas of sand that came away with the pattern but were small enough that I decided they could be fettled out before painting.
   
then the other half of the mould failed as I tried to put it in place. I abandoned the casting business for the day and went and spilt firewood.

I'm having a rethink of how I'm approaching this casting, I'm either going to pour it in two halves, or machine the other half from stock, and screw the two parts together. Time to back away and do something else for a bit though.

[TomG]

The good news is you didn't bang yourself in the nose with the flask when the mould failed.

It will definitely look amazing once you beat the process into submission.

Tom

[Dr Stan]

How about using the lost wax casting method?

[Pete O]

(06-11-2019, 12:44 PM)Dr Stan Wrote: How about using the lost wax casting method?

It did occur to me that some kind of sacrificial pattern might be better. I would definitely approach the letter thing differently if doing it again too. This is really something of a whimsical project, which is why I've tried to do it without spending any money, but I've put enough time into it for now. If we get some decent weather forecast again I might give it another look, I need a dry day to run my furnace and there's rain all week now.

[vtsteam]

Very late to this discussion and I've been away from casting for a long time now, too, but just in case the following info helps someone on a budget:

For block letters a half inch or more in height, I simply printed them out on paper, pasted that to cereal box cardboard, and cut them out with scissors and X-acto knife. Then pasted the cardboard letters in place on the pattern. A few coats of sanding sealer added a slight drafted radius to the bosses, and they worked fine. You can also laminate duplicates of the letters if more height is wanted.

For smaller simple straight lettering needs, I just used to make them with a cheap plastic Dymo label-maker -- the type that embosses a sticky backed plastic strip tape. I left excess and rounded the ends to look more like a traditional metal pattern strip and stuck that to the pattern.

Rounded plastic model letters, for railroading I believe, come in scaled strips. A little pricey, but they do look nice. I have some, but haven't used them yet.

[Pete O]

Thanks for that VSteam, I haven't been back to this little project since my last post here but i think the idea of much lower-profile lettering with just the thickness of a piece of card is very sound. This pattern was just way too crowded for the depth of the lettering.
I did try some lettering with some bodyfiller letters straight out of the rubber mould just to see how they would go with no modification, I was burying some taps (faucets for you!) into the front lawn and cast some lids for the holes.
   

This was the first of three, certainly good enough to stop the mower falling down the hole but no showpiece. Much more draft on the letters and much wider spacing between made a big difference to how they came out of the sand.

I love the Dymo labeller idea. I remember when those things were the latest must-have gadget.

[vtsteam]

That looks pretty good to me Pete!

Here are some letters I did with cardboard:

[Dr Stan]

Very nice indeed.