Rusty AC Drip Pan

[JerryRoss]

My AC condensation drip pan is rusting and causing a heavy rust stain at the through hull drain. I am planning to remove the drip pan and either paint or replace it, perhaps with aluminum or stainless. My AC is a Cruisair SXR16 self-contained unit mounted in a box in the lazarette. I would appreciate comments and tips from anyone dealing with this problem or removing the AC unit. Thanks.

[TBOT422]

Jerry,

I noticed similar problems on our AC unit this weekend when cleaning the air filters. From what I could tell first off, it appeared the drip pan may already be aluminum, and the rust may be coming from the mounting base of the compressor itself. I haven't had time to check it out, or even determine what model we have installed. I'll relay more when I've had time to investigate further. It may be a few weeks.

[JerryRoss]

Hopefully I have dealt with my rusting AC unit and the rusty stain at my through hull. I removed AC unit from boat, removed drip pan from rest of unit, scraped asphalt type coating from drip pan, sandblasted inside of pan, wire brushed bottom of compressor base, primed pan and compressor base with one coat Rust-oleum Rusty Metal Primer, then painted with two coats Rust-oleum Gloss White Protective Enamel. I took opportunity to also paint most of tubing, condenser and compressor with one coat white. I first wire brushed the asphaltic coating in the pan and primed and painted it but the coating bled through the paint and I was afraid it would not last so I scraped it all off. I found some rust under the asphalt type coating so I'm glad I scraped it off. I used liquid primer and paint, not the aerosol type. Attached are some pictures. The pan looked pretty bad (Pic 1) but most of that was just stain coming from the heavy, crumbly rust on the compressor base (Pic 6). The pan and compressor are the only ferrous metal in the whole unit. I built a device to support the condenser and compressor while working on them (Pics 2, 3, & 4) and wired the compressor base to the cooling coils to support it when I removed the condenser and compressor from the pan (Pic 5). Obviously one needs to be very careful to not break any joints on the refrigerant or water cooling tubing so help is required for some steps. I used a high tech device to support the compressor so I could remove the wires to brush and paint the base (pic 7). Pics 8 & 9 show the completed pan and condenser.

[TBOT422]

Jerry,

Are you going to be in FL anytime soon and fix our drip pan?

Just Kidding. It looks like a healthy project. How long did the project take?

Thanks so much for the pictures and descriptions, they will be a lot of help when I get around to tackling that project.

[JerryRoss]

Gary,

In total I probably spent 24-36 work hours on this project. However, that included several false starts and time trying to figure out how to accomplish specific steps. Second time around would probably take about 8 work hours. I have some pencil notes about how I removed the AC unit from the boat and dimensions for the jig to support the compressor and condensor. When you get ready to tackle the job, give me a shout and I will type up my notes and send them to you. I failed to mention, but when reinstalling the unit, I moved the temperature sensor which was clipped to the pan just behind the air intake vent to a new location near the salon ceiling in front of the galley sink. Now I run my AC fan in intermittent mode which is nice.

[TBOT422]

Jerry,

Follow up question for planning purposes. How long did it take to remove the unit from the boat? Later this summer after we get back from our spring cruise to nowhere in particular, I need to take the boat in to the boat yard to have bottom paint and some other minor repairs. If I could take the AC unit out and work on it in my garage while the boat is in the yard that might be a good schedule. Right now I'm thinking about doing that sometime in June or July, although it will probably be August the way my schedules go.

Priorities right now are cruise preparations . . . re-stitch the genoa, new starting battery, new light-wind sail (Doyle UPS), waterproof the bimini, defrost the frig, build a lower shelf for the frig to make the beer easier to access, check all the operational systems, stock plenty of pain killing refreshments . . .

Thanks

[JerryRoss]

Gary,

I believe I can now remove my AC unit in two hours or less but I know exactly how to do so and would not have to spend time studying anything. I will send you the procedures when I have time. I suggest you allow two hours plus one hour contingency to remove your unit, assuming it is exactly like mine and installed exactly the same way. Otherwise, it could take more time but i can't guess how much.

[JerryRoss]

As promised, detailed below are the procedures I used to remove, service and reinstall my AC unit. Obviously these are specific to my boat and AC unit. I have hull number 350 and my AC is a Cruisair SXR16 which was discontinued several years ago.

AC Unit Removal
1. In lazarette, remove 4" hose serving aft cabin from air distribution box on top of AC enclosure. To do so, loosen hose clamp and remove two ½" screws and washers from hose. Screws are at 0°and 180°horizontal and may be under duct tape. Cut X on top of screws and use Philips screwdriver to back screw out through the duct tape.
2. Remove 4" hose serving forward cabin from air distribution box on top of AC enclosure. To do so, loosen hose clamp and remove three ½" screws and washers from hose. Screws at 0°, 90°, 270° vertical and may be under duct tape.
3. Remove nine 1¼" screws holding AC enclosure lid to enclosure sides. Mine had no screw in 10th hole at forward port corner. I tried to remove fiberglass air distribution box on top of AC enclosure lid but it was glued in place, maybe with 5200, and the flanges were too flimsy to cut the glue without destroying the flanges.
4. Remove five 5/8" screws holding rectangular cabin air outlet box to rear of cabin bulkhead. Mine had no screw in sixth hole in bottom center of box. My cabin air outlet box was also fastened to the cabin bulkhead with silicon which had to be cut in later step.
5. In cabin, remove air inlet and outlet grills.
6. Working through cabin air outlet hole, use sharp putty knife to cut silicone holding rectangular air box to cabin bulkhead.
7. Working through cabin air inlet hole, remove duct tape and four ½" and one 5/8" screw and washers from blower exhaust hose. These five screws were all I could remove working though inlet hole. No apparent reason for different length screws.
8. In lazarette, raise rear of AC box top 2¼" and block with 1½" + ¾" wood and remove three more screws and washers from blower exhaust hose. I could not access these three working through cabin air intake hole.
9. In cabin and working through cabin air inlet hole, slip blower exhaust hose up and off blower exhaust housing.
10. Working through cabin air inlet hole, disconnect temperature sensor at front of AC unit drip pan and move to safe place so it won't be damaged while removing AC unit.
11. In lazarette, pull AC box top up and to rear and remove. The 6" hose and air box serving the cabin will still be attached
12. Ensuring AC power is off, open AC unit electrical box and disconnect power and pump wires. My screws are extremely tight. My power cable with L1 and L2 goes aft and my pump cable with P1 and P2 goes down. Mark wires and tape off L1 and L2 wires to prevent accidental shorts. Tape off AC breaker at panel to prevent it being turned on. Could shut off shore power AC breaker in port rear lazarette locker and/or disconnect shore power cable.
13. Remove two hose clamps from cooling water outlet hose and remove hose from AC unit. In process, my "phone" wire to unit control display disconnected from plug but no problem.
14. Clip plastic tie holding display wire and temperature sensor wire to water hose.
15. Loosen two hose clamps and remove water inlet hose and remove hose from AC unit.
16. Loosen one hose clamp and try to remove drain hose from plastic fitting on AC drip pan but cannot due to barbs on plastic fitting and tight space.
17. Remove four clamps holding AC unit drip pan to AC enclosure floor.
18. Move AC unit to port and then able to remove drain hose from plastic fitting.
19. Remove 5/8" screw and plastic clamp holding water hose to compartment floor.
20. Remove three 5/8" crews holding control wire to AC enclosure floor and then move wire to more safe location so it won't be damaged while removing AC unit.
21. Remove three self tapping screws holding blower case to evaporator coil enclosure, remove two similar screws from bracket at bottom of blower case (note starboard screw holds green ground wire), remove one screw holding bracket to AC drip pan and loosen other screw. Now remove second screw and remove bracket. Bracket screws are blunt.
22. Remove blower housing and motor which requires wires to be cut at existing splice.
23. In cabin and working through the cabin air inlet hole, slide AC unit to starboard so there is about 1½" clearance between drip pan and AC enclosure port side.
24. Working through cabin air inlet hole, raise port side of AC drip pan about ¾" and block up with wood piece. At this point the port end of the AC unit is pretty light so you can probably pick up on the evaporator coil enclosure to raise the drip pan. The intent is to provide space for your fingers to go under the pan later when you lift the unit while in the lazarette.
25. Position someone to work through cabin air inlet hole and put wooden blocks under AC unit as you lift it while in lazarette. Note the AC unit center of gravity is essentially under the compressor so position supports in that area. Use large flat supports because unit must be raised quite high and small supports will be unstable and unsafe for assistant.
26. The objective now is to lift and support the AC unit until the unit top reaches the lazarette roof. As explained below, this will require a bit of tilting and twisting of the unit. Also, you will probably have to experiment a bit to find the right combination of support sizes and thickness based on how far you can lift the unit in each increment. Proceed as follows.
27. Standing in lazarette, lift the AC unit with your left hand under the drip pan port end and use the cooling water tubes as a handle for your right hand. Lift the unit as much as you can and have assistant add support blocks. I found I could lift the unit about eight or nine inches in the first increment before the lazarette top began interfering with my right arm and elbow.
28. In cabin and working through cabin air inlet hole, remove plastic elbow in drip pan outlet for drain hose. Remove the elbow to prevent damage.
29. Standing in lazarette, begin lifting AC unit with both left and right hands under the AC drip pan and add supports as you lift. To do this, I leveraged my right forearm on top of the AC enclosure rear wall and lifted the unit about ¾" in each increment. Then I repositioned my forearm and lifted another increment. A stronger person in the lazarette and/or with stronger help working though the cabin air inlet hole, a better technique might be employed.
30. Continue lifting and blocking until the AC unit starboard end reaches the lazarette top. At this highest point the drip pan bottom will still be below the enclosure walls.
31. Twist the AC unit as much as possible so the starboard end is forward and port end is aft.
32. In one continuous lifting and twisting motion, lift the drip pan port end above the enclosure side, pull the port end aft, push the starboard end forward, and lift, tilt and pull the entire unit up over the enclosure side and balance it on the enclosure side. Now lift and slide the unit until the compressor end is sitting on the port aft corner of the AC enclosure and the evaporator end is on the edge of the lazarette where the lid closes. Exercise care to not pull off the rubber insulator pad on the drip pan bottom. This step is actually a bit easier than it sounds but will require lifting, tilting and twisting of the unit to clear the lazarette sides and roof.
33. Remove AC unit from boat and service as required
34. Remove as much silicone as possible from the rear of the cabin bulkhead around the exhaust air hole and from the rectangular exhaust air box that connects to the rear of the main cabin bulkhead.

Service AC Unit
1. Removed AC unit from drip pan and mount unit on suitable holding device.
2. Pursued purchasing a new drip pan but found none available. Talked with Dometic Corp Environmental Division at 954-973-2477, Sea Air at 850-453-2888, AER at 281-474-3276 and Cruisair Southeast at 954-920-0300. Learned that my SXR16 unit was discontinued several years ago and replaced with the STX16HV unit..
3. Then pursued having a new stainless steel drip pan made and could have for about $250, but finally decided to clean and paint my existing drip pan.
4. First cleaned AC drip pan by brushing and washing asphalt type coating and then painted it with Rustoleum Rusty Metal Primer and painted with Restoleum White Enamel Paint. However, the asphalt type coating bled through the primer and paint and I was concerned it would not last.
5. Then cleaned AC drip pan by scraping off enamel, primer and asphalt type coating and sandblasted the pan.
6. Cleaned AC unit and removed rust from compressor base with file, scraper and wire brush.
7. Primed compressor base and drip pan with two coats Rustoleum Rusty Metal Primer.
8. Painted most of AC unit with one coat Rustoleum White Enamel and painted compressor base and drip pan with two coats same enamel.
9. Reinstalled AC unit onto drip pan.
10. After several weeks AC use, observed that paint on floor of drip pan has a rough orange peel texture rather than the original smooth texture. Now concerned the Rustoleum may not last very long and that it is not designed to be submerged. In hindsight, probably should have invested in some type epoxy paint or other paint suitable for being submerged because floor of drip pan has about 1/8" standing water due drain hole position.

AC Unit Reinstall
1. Sit AC unit on lazarette opening and port rear corner of AC enclosure.
2. In cabin and working through cabin air inlet hole, have someone position supports under AC unit so unit can be sit on blocks and AC enclosure sides. Note the AC unit center of gravity is essentially under the compressor so position supports in that area.
3. In lazarette and with supports under AC unit, slide AC unit and supports to starboard while twisting unit so starboard end is more forward than port end. Twisting is necessary to clear lazarette sides and roof. Slide AC unit in as much as possible but you can not get in all the way at this point. AC unit will now be at somewhat of a diagonal to enclosure.
4. Standing in lazarette, pick up AC unit by picking up AC drip pan while leveraging right forearm on top of AC enclosure rear wall, have someone remove about four or five inches of supports, tilt AC unit starboard end down, twist and slide AC unit into enclosure and sit on remaining supports. This is actually easier than it sounds but go slow and think through every step before proceeding. Also, be sure the amount you need to lower unit at any time is within the range you can tilt your forearm and wrist down.
5. Now AC unit should be completely inside enclosure walls and setting on the supports.
6. Repeat Step 4 as necessary to remove supports so AC unit is sitting on about eight or nine inches of supports.
7. In cabin and working through cabin air inlet hole, install plastic elbow in drip pan outlet for drain hose.
8. Standing in lazarette, lift the AC unit with your left hand under the drip pan port end and use the cooling water tubes as a handle for your right hand. Lift the unit and remove all supports sit the AC unit on the enclosure floor. In this step, do not try to leverage forearms but just pick up the unit.
9. Install water hoses, install electrical wires, install AC drip pan hold down clamps, install control wire to display and fasten to enclosure floor, and install temperature sensor wire. I elected to move temperature sensor to a new location forward of the cabinet above the sink counter so I connected a 20' phone wire between the AC unit electrical box and the 3' existing temperature sensor wire. The AC manual recommends this if you want to run the AC unit fan in intermittent mode.
10. Install the blower unit and motor. I elected to add a one-foot section of new wire to the blower wires coming from the control box and then put disconnects on that wire and the wire from the fan motor. I did this to give more slack for maneuvering the fan.
11. Test AC unit to ensure all is well and there are no water leaks.
12. Put foam rubber air seal material on the rectangular cabin air outlet box that connects to the cabin bulkhead. I used stick-on foam tape from hardware store. This box should still have the 6" air hose connected to it and to the air distribution box on top of the enclosure lid.
13. Sit the AC enclosure lid on top of the enclosure sides and connect the 4" air hose serving the forward cabin to the air box. This requires compressing the 7" air hose on bottom of the enclosure top that eventually will connect to the blower. Connect the 4" hose serving forward cabin at this point because you will probably need to move the enclosure lid around to get to all screws.
14. In the cabin, have someone work through the cabin air intake hole above the refrigerator to guide the 7" hose onto the AC blower as you lift and lower the enclosure lid or top in place. Now insert and tighten lid screws. Because the 7" hose fits so tight on the blower housing, I elected to not try and put the screws back or install a hose clamp. That did not seem necessary and probably was impossible.
15. Connect the 4" hose serving the aft cabin to the air distribution box on the enclosure lid.
16. Connect the rectangular cabin air outlet box to the cabin bulkhead.
17. Have twenty beers.

[SubVet]

Great information...