I’m sure many of you who have picked up the NTSU RBA, (or the SXK style), have run into the same love-hate relationship I’ve experienced 
... On one hand, the flavor and machining are top-notch, and on the other, well ... them juice ports are just insanely massive.
If you aren't running a 3.5mm+ coil with a bow-tie wicking style, it’s a flood-fest, and even with a massive coil and some fairly finicky wicking, it's pretty much guaranteed to dump a tank on occasion ... Even worse ... because the tolerances between the RBA and a Boro / Boro style tank are so tight, just by sliding the bridge into the tank often snags the cotton, disturbing the seal, leading to a leak before you’ve even taken a puff
The "Over-Engineered" Alternatives
I spent a lot of time looking at how to fix this "properly," and if you have access to a machine shop, you’ve probably considered these too:
The Solution: The "Floor Fill" Fix
The real issue isn't just the port size; it’s the depth of the wicking detents on the deck. There is way too much empty volume under the wick where juice pools and surges.
The Fix: Use a small amount of Food-Grade, High-Temp Moldable Silicone to fill the bottom of the wicking detents, (the two "wells" on the deck).
Why it works:
Mechanical Support: It effectively "raises the floor." Your cotton now has a rubber shelf to sit on.
No More Wick-Drag: Because the cotton is supported from beneath, it stays put when you slide the RBA into the tank. No more snagging on the tank walls!
Perfect for 2.5mm Coils: You can now run smaller IDs with standard wicking, and the reduced juice reservoir prevents flooding while keeping the wick perfectly saturated.
Safety Note: If you try this, make sure you use Food Grade Silicone ... Avoid Supermarket RTV as it off-gasses acetic acid, unless you're into old school slap chips flavour
I’ve been testing this for a bit now and it has turned the NTSU from a POS fiddly leaker into a reliable flavorful bridge, so if you've got one gathering dust because of wicking issues, give this a shot
Curious to hear if anyone else has tried something similar and or found other ways to tame this bridge.
... On one hand, the flavor and machining are top-notch, and on the other, well ... them juice ports are just insanely massive.If you aren't running a 3.5mm+ coil with a bow-tie wicking style, it’s a flood-fest, and even with a massive coil and some fairly finicky wicking, it's pretty much guaranteed to dump a tank on occasion ... Even worse ... because the tolerances between the RBA and a Boro / Boro style tank are so tight, just by sliding the bridge into the tank often snags the cotton, disturbing the seal, leading to a leak before you’ve even taken a puff
The "Over-Engineered" Alternatives
I spent a lot of time looking at how to fix this "properly," and if you have access to a machine shop, you’ve probably considered these too:
- Shortening the Chamber: Machining down the chamber floor and turning a custom longer chimney. This works but it's irreversible and a massive, (costly), amount of work.
- Internal Sleeves: Turning a PEEK or SS316 ring to act as a "shutter" for the ports. Great in theory, but incredibly fiddly to get a perfect friction fit without hitting the posts.
- The "Wick Stuffing" Method: The common advice offered out there is just "use more cotton." But let’s be honest now ... stuffing a 2.5mm coil with enough cotton to plug those holes tighter than a frogs butt at 10 meters underwater usually leads to a host of other @#$%
The Solution: The "Floor Fill" Fix
The real issue isn't just the port size; it’s the depth of the wicking detents on the deck. There is way too much empty volume under the wick where juice pools and surges.
The Fix: Use a small amount of Food-Grade, High-Temp Moldable Silicone to fill the bottom of the wicking detents, (the two "wells" on the deck).
Why it works:
Mechanical Support: It effectively "raises the floor." Your cotton now has a rubber shelf to sit on.
No More Wick-Drag: Because the cotton is supported from beneath, it stays put when you slide the RBA into the tank. No more snagging on the tank walls!
Perfect for 2.5mm Coils: You can now run smaller IDs with standard wicking, and the reduced juice reservoir prevents flooding while keeping the wick perfectly saturated.
Safety Note: If you try this, make sure you use Food Grade Silicone ... Avoid Supermarket RTV as it off-gasses acetic acid, unless you're into old school slap chips flavour
I’ve been testing this for a bit now and it has turned the NTSU from a POS fiddly leaker into a reliable flavorful bridge, so if you've got one gathering dust because of wicking issues, give this a shot
Curious to hear if anyone else has tried something similar and or found other ways to tame this bridge.
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