I want to talk about my experience on DIY ( sorry about some English mistake )
1- Why my ejuice suddenly has nice smell but bad taste ( like chemical or iron taste ) even after steep long time !!
please check screw on RDA or RTA , the rust is reason , you need to change screw , and check coil if it old you need change it .
also you should steep it well and breath it ( cap off ) for 30min to 2 hour maybe more if you still taste chemical taste
2- Why my recipes mute flavors !!
for me I see the best way to steep ejuice and keep flavors strong , by the time and little squees after steeping .
no microwave , no warm bath , no milk frother , no ultrasonic .
only the time is best way and keep flavor strong for longer time .
also sometime more sweetener mute flavors .
hello sir it’s nice sharing your experience with others
in addition to 1:
never happened to have rust on screws or anywhere in the deck… though in my experience from i have seen to other users
a) the decks should be cleaned often… not just changing cotton and wire… i have noticed many people specially the ones that using RBA’s don’t clean the rba but just the tank and base… this is something that i have noticed being done by many people… i gues sthis is happening because most people don’t have a second rba or they want just to place inside a new wire and cotton to vape asap… this method can drive to muted taste even to a really bad taste… no matter what if it’s an RBA/RTA/RDA should be cleaned very well oftenly… as you said if there is any rust, should be removed too also to comment, having rust inside a tank doesn’t seem a very healthy practice for vaping…
muted flavors… this is a harder problem to solve…
a) from times to times i warm bath my VG (i mix high VG juices on large batches up to 1liter, (yes i am too lazy mixing all the time while i consume a fair high amount of ejuice/day) for making it kinda easier to shake the bottle so flavors can be mixed easier with the rest ingredients… i would consider this practice as safe and doesn’t mute flavors (for me) though warm baths, microwave as your said is a bad choice for certain flavors…it can change the results very very much up to destroying the end result… the best steeping/aging method is doing it naturally… placing the mixing ingredients, shaking them and letting them steep…
b) muted flavors could be have dealing with a dirty tank too
c) quality of ingredients (bad VG/PG quality (specially VG)) and flavors too… we all have to make sure that we are storing our vaping stuff correct for not having these issues…
d) underflavoring or overflavoring can lead to muted flavor too… more flavor doesn’t always mean better flavor…
e) steeping… some flavors need more time to shine… some other not…vaping a juice before it’s fully steeped can cause muted flavor
f) in general in good balance in flavors is a must to… and i will take a example of two random flavors… let’s say “sweet cream (TPA)” and "strawberry ripe (TPA), while sweet creams needs like 20 days to start poping out, at the same time strawberry is losing it’s strength… it’s also good taking that kind of “problems” in consideration… a little bit MORE strawberry could solve the problem
muted flavors is a big problem when it happens… there are many factors that play role in this…the ones i posted are just some i could fast think of
@Adam89 I get that “iron” taste from Kanthal wire coils. Look into Stainless steel coils or ceramic or titanium. Search in the upper right Search box here (Magnifying Glass icon)
try N80 , it is better than Kanthal wire
N80 need longer time than Kanthal to rust and it better for flavors
but Kanthal good for series coil build like fused clapton , it is no need more wrap like N80 .
N80 no bad taste like kanthal after time.
you cant use SS316 or titanium for RDA low ohm , it is will burn quick .
it’s nice sharing your experience with others 
