There is no possibility to enchant crafted piece of armor / weapon
They absolutely can be enchanted but the glyph level can be no higher than the gear piece's level. Since mat tiers for the gear crafts change at Levels 16, 26, 36, 46, etc. You can get close to the gear's level, but enchant levels generally move in increments of 5 (Jode and Jora being the oddballs at Level 1 and there being no Level 45 runes), so if you're holding down mats cost by crafting gear at the tier transitions, then your glyphs will be minimally 1 level below the gear you crafted and a big gap between Level 41 and CP10 with nothing covering that spread.
I'm fresh out of outrage, but I could muster up some amused annoyance if required.
Right click on item you wish to enchant > Pick "Enchant" from the drop down list and either you will see any enchants/glyphs you have that are the right level for that item or you will see the message "you do not have any enchantments that can be applied to this item".
If you see the latter message you need to either acquire or craft a glyph of the correct level range for the item.
The post above explains the available level ranges.
Typically it can be quite hard to purchase pre-made glyphs for the lower levels, whilst Truly Superb Glyphs which are for max level(CP160) can usually be purchased from many Guild Traders.
When people say to me........
"You're going to regret that in the morning"
I sleep until midday cos I'm a problem solver!