I have been pleased to see this thread appear. I have recently returned to slot cars for my entertainment and the benefit of my grandchildren, my only experience of slot cars being as a teenager in the early 60's and with my own children in the late 70's. I have never enjoyed seeing layouts cramped into a corner of a room tail chasing with another of my modelling interests, railways, thus decided to contemplate a garden layout. Initial enquiries were met with comments to the effect that no-one does it because it cannot be done. That was a sufficient challenge to me, but I remained confident that others must have tried it, and lo and behold some have appeared in this thread, thanks.
I have little to offer so far being in the very early development stages. I live on the edge of the Brecon Beacons in South Wales thus my main problems are likely to be rain and cold. I intend to make it modular in order that it can be taken under cover for winter or prolonged periods of bad weather, but it must be capable of withstanding a Welsh summer. Recent unseasonal weather has produced problems of heat rather than the more generally expected rain. I had thought of routing tracks to give realistic curves, but considered that the problems of weatherproofing wood or MDF unsurmountable. I thought through routing plastic, but slot drainage would be a problem. Initially I just wish to 'get something going'. Consequently I have settled on trials with Scalextric track, and have probably inflated its price on the dreaded Ebay by recently purchasing a lot of track. Being too decrepit to crawl around the floor I am laying it on waist high shelving, I am tacking it to the shelving, pulling the joints apart to their maximum tolerance to allow for expansion, and covering the rails with copper self adhesive tape for good conductivity, and to make a smooth transition over rail joints. It has been out in recent heat, dew at nights and at the beginning of April over some frosty nights, the copper does discolour slightly, but this has not affected electrical contact, and in any case a wipe over with either a methylated spirit rag or WD 40 brings back a shine. I am waiting to see how long it will be before the adhesive starts to fail, particular if the steel rail corrodes underneath. The rubber has buckled slightly during the recent hot days, but I only wish to run childproof bangers for the children, or my recently acquired Scalextric classics, D Type, Mercedes and Mini, and an uneven surface makes them appear more realistic. I have reduced power to achieve scale speeds for the later, and prevent my grandchildren from continually coming unstuck.
Once I have ironed out running snags I shall add some 'Goodwood' type scenery in the immediate environs of the track, but the backdrop remains the non descript greenery of garden hedge and bushes, it being in a semi enclosed small area at the side of my house mainly for some cover from weather, and privacy and security for the children. Overwinter I hope to kit build some of the lovely classic cars on the market. Eventually I may well wish to digitise the layout, but shall arrange it so that sections of electrickery wizardry can be easily removed to cover. Other than that I am waiting to solve the next problem, if this thread continues to run I shall add my experiences as and when they arise.