Bottling Imperial Stout

Its been in the primary for 4 weeks, and I am about to rack it into the secondary with vanilla, oak chips, and a small amount of coffee. Lately my bottles have been too foamy. I have been using table sugar and using less and less. What should I do to bottle this? Do I need to add sugar or will this self carb?

WHat do you mean you've been "adding table sugar and less and less?" Are you talking about putting sugar in each bottle at bottling time? How much are you adding?

To get certain level of carbonation you need to be pretty precise in you measurement. There are calculators to help you figure it out, and it's based on the coldest temp your beer was during the process. The amount can be figured out based also on style. Though most new brewers start out with a set amount of priming sugar (usually 4.5-5 ounces) which produces around 2-2.5-volumes of co2. WHich is average for most beers.

The best way to get a consistant level of carbonation is to bulk prime, by adding the measured amount of sugar to about 2 cups of water, bringing it to a boil, letting it cool and adding it to a bottling bucket while you are transfereing the beer from fermenter or secondary, the sugar solution will mix pretty evenly with the beer at that point, and you will have pretty much even carb across the board.

If you are bottle priming, and getting sime foamy bottles, then you are probably addin too much sugar to some bottles. It's really hard to get accurate measurement in each bottle.

I go into more detail about bottling in here https://www.homebrewtalk.com/f35/bottling-tips-homebrewer-94812/

It really depends on the style and gravity of the beer in terms of not adding any sugar. With really low gravity beers, you could let it carb on it's own, in fact some beers like british mild, when you are using a carbonation calculator in brewing software, show no sugar is necessary.

But in the case of an imperial stout, which is a high grav beer, you would just end up with flat beer.

Its all bulk primed in the arboy, during the transfer. Calculated on tasty brew. volume x fement temp x style etc.... I have been adding less cause they have a ginormus head, that lasts forever, and even sometimes, 3/4 head. So I have been doing 3/4 of what they say and its still too much. I think table sugar is just too strong, cause dextrose took longer, but kept a nice small head.

why don't you try using light dry malt extract (DME) to carbonate instead of table sugar. Your problem probably has to do with the table sugar. But is it possible that your vanilla has sugar in it? Some extracts are sweetened, which if not fermented could cause a little extra cO2 when you bottle.

The problem has nothing to do with the type of sugar. That is just BAD advice, don't take it.

Carbonation != head formation

Maybe you should reconsider the way you're pouring the beer.