Im working on my first cobblestone road and Ive used double stick tape on the base and have stuck down the lentils to the tape. My question is what is the best technique and what kind of filler to use as grout and how to apply it without destroying the layout.

Hey there major well for filler on a coblestone road i would use wall filler the kind that you mix up. its thin and can be spread over the area easily plus it will sink right into the cracks. hope this helps got anymore questions just ask!

Graeme

Here's a link:
I believe Keith covers the construction very well.
https://armorama.kitmaker.net//features/690

If you read the article, cobblestones, and the mortar are cover on page 3

I did not use double sided tape when I did my lentil road. I just glued them down with Elmer's. There must a a good reason to use double sided tape, though I don't know what it would be. I used the dry spackle or wall patch you can get at your favorite DIY store, mixed it up a bit on the dry side and grouted with that. Before it was dry I wiped the excess off with a rag and then a stiff (disposable) brush.

Worked out great.

Six months after the diorama was finished a critter in my basement, probably a mouse, ate half my stree, paint, spackle and all. And yes, that is true. I wouldn't make up anything that stupid.

Shaun

Me, I did it the old fashioned way. I found one of those resin sheets of cobblestone roads that the archetects use at my LHS and glued it down. Keith Magee himself was absoluely amazed at how good it lookeed when he saw it at a show.

:-) :-) Lentils, split peas, beans, what ever dried bean type you choose, with germinate and start to grow..... when exposed to too much moisture....... :-) :-)
Years ago, I used split peas, glued each one down ever so nicely, a soupy mixture of plaster, and it looked really good, until little pea spouts started....... :-) :-) rolling on floor.

I tried this method as well, a few years ago. I used the double sided sticky tape, placed a few hundred lentils and then added my grout mixture. It was a little on the damp side and the skin on the lentils started peeling, and lifting up. Scary site, seeing two evenings of work decomposing in front of your eyes.
So learn by my mistake ... keep the grout on the dry side and remove the skin layer!

Why not just use plaster of paris. The cobblestone effect can be recreated by scraping the patern on the surface with a sharpened round tip, ie an old screwdriver...

You can try using those super compressed styrofoam boards too... just use a ball-point pen and scribe the shape you want for your cobblestone groundwork, apply the putty+color and there you have cobblestone groundwork... beware (lots of time required... but cheap)