If you have spent any time degassing epoxy or silicone, you already know the Robinair name. It is the pump HVAC techs trust, and that reputation follows it onto resin benches across the country. The short answer to whether you should buy the 15310 for resin work is this: it degasses flawlessly, and it will likely outlive every other tool in your shop — but for degassing resin alone, you are paying a 2-3x premium over an import pump that pulls the exact same vacuum into the exact same chamber. That tension is the whole story of this pump, and it is worth understanding before you spend $200-$260 instead of $90.
This is not a knock on the 15310. It is a genuinely excellent machine. The question is simply whether its excellence is aimed at the job you are actually doing. For degassing resin, the physics ceiling is set by your chamber, not your pump — and that changes the math entirely. Let’s walk through the data.
What the Robinair 15310 actually is
The 15310 is a single-stage rotary vane vacuum pump built for air-conditioning and refrigeration service. It moves 3 CFM of free air, spins a genuine 1/3 HP motor on 110V/60Hz, and pulls a factory-rated ultimate vacuum of 75 microns — roughly 29.9 inHg. The body is cast aluminum, not the thin pot-metal casting you find on bargain pumps, and it is rated to evacuate A/C systems up to 10 tons (35 kW). It is CSA-approved and carries a one-year warranty backed by a real US parts and service network. Full numbers are in the specs below.
In other words, this pump was engineered to spend years doing demanding HVAC work, where pulling moisture out of a refrigerant line at a deep, stable vacuum genuinely matters. Degassing resin asks far less of it. That mismatch — a serious HVAC tool doing a light hobby job — is exactly why it works so well and why it is arguably overbuilt for the task.
How it stacks up against the field
The comparison table puts the 15310 next to four reference points: the two-stage Robinair 15500 step-up, two popular import single-stage pumps (the Kozyvacu TA350 and a generic VEVOR 3 CFM), and Robinair’s own economy 15300.
The pattern jumps out immediately. For ultimate vacuum — the number people obsess over — the 15310’s 75 microns is identical to the import pumps. The VEVOR 3 CFM is rated at roughly 75 microns; the Kozyvacu TA350 lists 5 Pa, which lands in the 75-150 micron range. None of these three will be the limiting factor when you degas. What separates the Robinair is the 1/3 HP motor (versus 1/4 HP on the imports), the cast-aluminum build, and the weight — 18 lb versus 9-11 lb for the imports. You are buying a heavier, more durable machine with more motor headroom, not a deeper vacuum.
Why 75 microns is already overkill for resin
This is the single most important thing to understand before spending Robinair money. Degassing works by pulling enough vacuum that dissolved air and stirred-in micro-bubbles expand, rise to the surface, and pop. The threshold for that is around 29.6 inHg — very close to a full atmospheric vacuum, but not deep in the absolute sense.
The 15310’s 75-micron rating equals about 29.9 inHg, so it clears the degassing threshold with margin. So does a $90 import. And here is the kicker: your chamber almost certainly cannot hold that vacuum anyway. A typical acrylic-lid vacuum chamber with a rubber gasket leaks down to only about 700-800 microns in real-world use — roughly 10x shallower than what the 15310 can pull. The pump is not the bottleneck. The chamber seal is.
That is why a two-stage 20-micron pump buys you nothing for degassing. Both the 75-micron 15310 and a 20-micron two-stage pump sit far below your chamber’s 700-800 micron ceiling, so neither runs out of depth. The vacuum you actually achieve is decided at the gasket, not the vanes. If you want better degassing results, the upgrade that moves the needle is a thicker, better-sealing chamber — not a deeper pump.
Degassing performance in practice
Where the 15310 earns its keep is evacuation speed and steadiness. Its 3 CFM pulls a 3-5 gallon resin chamber down to working vacuum in roughly 1-2 minutes. That speed matters more than people expect: the faster you reach full vacuum, the more pot life you have left before the resin starts to kick. With a slow pump, a fast-setting resin can begin thickening before the foam has fully risen and collapsed.
Expect the usual degassing behavior — the resin will foam up dramatically as trapped air expands, climb toward the chamber lip, then collapse back down. The 1/3 HP motor holds vacuum without bogging as that foam load changes. For reliable single-pull degassing, plan on a maximum pour depth of about 1 inch; deeper pours trap air faster than a single vacuum cycle can clear it and are better handled with thin-pour deep-pour resins or staged layers. None of this is unique to the Robinair — it is how degassing physics works — but the 15310 does it with a calm, planted feel that cheaper pumps do not always match.
The price question: what $200-$260 actually buys
Here is the honest accounting. At $200-$260 street (MSRP around $290-$310), the 15310 costs roughly 2-3x a comparable 3-3.5 CFM import. For that premium you are not getting deeper vacuum — you are getting:
- A cast-aluminum HVAC-grade body instead of a hobby-grade casting
- A genuine 1/3 HP motor with more thermal headroom for long runs
- A one-year warranty and a real US parts/service network
- Robinair Premium High Vacuum Oil that is easy to source
- Resale value and brand trust if you ever sell it on
If you also do air-conditioning work, every one of those features is usable, and the 15310 becomes a smart dual-purpose buy. If you will only ever degas resin and silicone, none of the HVAC engineering touches your actual workflow, and the money is better spent elsewhere — a thicker chamber, fresh oil, better mixing technique. There is no shame in either choice; it just has to match your real use.
Oil, maintenance, and shutdown discipline
The 15310 holds 8.5 oz (250 ml) of oil — on the smaller side, which means more frequent checks. Use a proper high-vacuum pump oil; Robinair Premium High Vacuum Oil is the matched choice, and the pump also accepts mineral, ester, alkyl-benzene, and PAG oils. Do not substitute 30W motor oil — it will not hold the rated 75-micron vacuum.
Resin work is harder on oil than HVAC work. Degassing pulls resin solvent vapor and ambient moisture into the reservoir, so the oil turns milky far faster than it would servicing A/C systems. Plan to change it roughly every 15-20 running hours, or any time it looks cloudy. The angled drain valve plus top fill port make the job quick and complete.
One habit the 15310 demands: it has no automatic anti-suckback isolation valve. Always close the chamber valve before you shut the pump off. Skip that step and atmospheric pressure can pull oil backward into your vacuum line. It is a thirty-second discipline, but an important one.
Single-stage versus two-stage: the 15310 vs the 15500
People reflexively reach for the two-stage 15500 thinking “deeper is better.” For resin, it is not. The 15500 reaches 20 microns and moves 5 CFM versus the 15310’s 75 microns and 3 CFM. On paper that is a meaningful jump. In a degassing chamber it is wasted: your 700-800 micron leak-down ceiling sits far above both pumps’ capability, so the extra depth never gets used. The 15500’s faster 5 CFM evacuation is a minor convenience on larger chambers, but it does not change the quality of your degassed pour.
Buy two-stage only if you also evacuate A/C systems, where sub-25-micron pull-down genuinely matters for removing moisture. For resin and silicone, the single-stage 15310 is the smarter, lighter, cheaper choice within the Robinair line.
Who should buy it — and who should not
Buy the 15310 if you fall into one of two camps. First, the A/C crossover user: if you service refrigeration or auto A/C as well as degassing resin, this pump does both jobs properly and the premium is justified. Second, the buy-it-for-life buyer: if you want a name-brand tool that will run for a decade with predictable parts support and you are happy to pay for that peace of mind, the 15310 delivers.
Everyone else — the maker whose only vacuum job is degassing resin and silicone — should look hard at a quality import first. A $60-$110 VEVOR or Kozyvacu pulls the same 75 microns into the same chamber, and you can put the savings toward equipment that actually changes your results. See our full resin equipment reviews and the broader reviews hub for chamber pairings and import alternatives.
Safety note
Always run a vacuum pump in a ventilated area: degassing releases resin solvent vapor through the exhaust, and the oil mist that comes with long runs is best vented or captured with an exhaust filter. Inspect acrylic chamber lids before each session — vacuum stresses acrylic, and a crazed or scratched lid can fail under load. Wear eye protection any time a chamber is under vacuum. These are general handling precautions; follow the pump and chamber manufacturers’ instructions, which take precedence over any general guidance here.
Verdict
The Robinair 15310 is one of the easiest pumps in this category to recommend on quality and one of the hardest to recommend on value — depending entirely on what else you do with it. As a degassing tool it is flawless and overbuilt; as a resin-only purchase it is an expensive way to buy a vacuum your chamber cannot fully use. Know which buyer you are, and the decision makes itself.