Buying & Building a Medium Ambulance into an RV – The FAM-BULANCE
- Thread starter rlrenz
- Start date
rlrenz
Explorer
I did some measuring, and the idea of a sideways shade will remain an idea - my side window is wide enough that a sideways shade wouldn't work, so it's back to the RV vertical shade store.
In other news, I asked my Freightliner contacts how much clearance there was between the headliner and the cab roof. They told me that I could plan on a maximum of about 7/8 - 1". They recommended using Riv-Nuts to attach anything to the roof to avoid having to remove the headliner (it saves them time, and it saves me from potential disasters).
My batteries seem warm and happy now - I have a 7.2 amp NOCO battery charger/maintainer connected to them through an always-on 12 volt receptacle. I set the charger on top of the module so I can see it from the outside, so I check the pilot light every few days. So far, so good. As soon as the weather turns to higher temperatures, I'm installing a pair of Xantrex 40 amp chargers - they are designed to be connected in pairs, so I'll wind up with 2x40 amp = 80 amp of 12 volt charger. The Xantrex chargers are designed to serve as battery maintainers as well, so I can safely leave them connected continually. I'm also planning to install a Xantrex 10 amp charger just for the separate deep cycle battery. The NOCO charger will be packed away in an on board tool box as a just-in-case charger. Since the Vanner inverter is connected to the batteries through a #2 cable, I'm going to use that as my battery connection for the chargers - I'm building a 1 ft long insertable cable with Anderson connectors at each end, and a heavy terminal post in the middle for the charger connections. Fusing will be done through Blue Sea post-mounted fuses, so each Xantrex will be protected against something ugly happening.
In other news, I asked my Freightliner contacts how much clearance there was between the headliner and the cab roof. They told me that I could plan on a maximum of about 7/8 - 1". They recommended using Riv-Nuts to attach anything to the roof to avoid having to remove the headliner (it saves them time, and it saves me from potential disasters).
My batteries seem warm and happy now - I have a 7.2 amp NOCO battery charger/maintainer connected to them through an always-on 12 volt receptacle. I set the charger on top of the module so I can see it from the outside, so I check the pilot light every few days. So far, so good. As soon as the weather turns to higher temperatures, I'm installing a pair of Xantrex 40 amp chargers - they are designed to be connected in pairs, so I'll wind up with 2x40 amp = 80 amp of 12 volt charger. The Xantrex chargers are designed to serve as battery maintainers as well, so I can safely leave them connected continually. I'm also planning to install a Xantrex 10 amp charger just for the separate deep cycle battery. The NOCO charger will be packed away in an on board tool box as a just-in-case charger. Since the Vanner inverter is connected to the batteries through a #2 cable, I'm going to use that as my battery connection for the chargers - I'm building a 1 ft long insertable cable with Anderson connectors at each end, and a heavy terminal post in the middle for the charger connections. Fusing will be done through Blue Sea post-mounted fuses, so each Xantrex will be protected against something ugly happening.
patoz
Expedition Leader
Since I'm not planning on ripping out the inside of mine, I'm going to use 1/4-20 Riv-Nuts for attaching anything on the outside unless it's something load bearing like steps or a ladder. I'm looking at Riv-Nut tools on Amazon right now, but not sure which is the best one to get.
You may have mentioned this already, but how many batteries and banks are you using? You probably already know all of this, but I had no idea the cable lengths and 'balancing the system' was so important. Check out this article:
How to correctly interconnect multiple batteries to form one larger bank
You may have mentioned this already, but how many batteries and banks are you using? You probably already know all of this, but I had no idea the cable lengths and 'balancing the system' was so important. Check out this article:
How to correctly interconnect multiple batteries to form one larger bank
rlrenz
Explorer
Riv nut tool: I bought mine from Grainger, but McMaster and Amazon would probably have comparable tools. I have two of them - one is a Marson hand tool for close quarters, and the other is a large Marson for larger Riv-Nuts. The McMaster part number is 95603A770 (www.mcmaster.com), and I see that Amazon has pages of them, probably with many being imports. Regardless of who the manufacturer is, be sure that you can get different sized mandrels if they aren't included with the tool - I have mandrels from 10-32 to 3/8". Riv-Nuts can be reasonably priced (particularly when the alternative is a very ugly tunneling project to get to the rear side of whatever) - I stocked up about 4 years ago when Grainger was changing their supplier, and they had blow-out prices. Riv-Nuts are available in steel, stainless steel, and aluminum - all available in open and closed end versions. Lengths vary according to the metal thickness. Closed end are intended for locations where you need to keep water out, but an open end Riv-Nut with some silicone can be used in probably 95% or so of the applications. I try to use the heavy duty Riv-Nuts whenever I can since they are knurled and get a pretty good grip, but regardless, I wipe some epoxy on the side of the nut before I install it to help ensure that it will stay there. When you start tunneling into an ambulance, you will find that the side skins are about 0.010" (1/10"), and that a Riv-Nut will do the job for darn near anything.
When you install a Riv-Nut, drill the right sized hole (it needs to be a clean, circular hole). I use a step drill to get it as close as possible, then a final pass with the exact drill specified. For instance, a 1/4" knurled Riv-Nut (McMaster 95105A143) requires a 25/64" hole. Since this is 1/64" larger than 3/8", I drill the initial hole to 3/8" with a step bit, then a final pass with a 25/64" bit. Once you drill the hole, you can see the hole thickness, and pick the right size Riv-Nut. I like to drill a trial hole in a chunk of scrap aluminum so I can verify that I have the right stroke set on the installation tool.
I've used Riv-Nuts on aluminum military radio shelters where there was no other way to install a screw - the shelters use a sandwich construction with an 0.050" aluminum inner layer bonded to 2" of urethane foam - they did the job perfectly.
On to batteries: I have the advantage that my battery installation was designed by Medic-Master/Freightliner. I have four Group 31 batteries in parallel for both engine start and to run the module when the engine isn't running. Since the module includes a lot of internal lighting (at about 5 amps per bulb) and external warning and scene lights, the ambulance has a 270 amp engine alternator. There is a test tag in the module that shows the actual power demand with everything operating (236 amps), and with optional equipment shut down (164 amps). Various ambulance designs use from 2-4 batteries, with the smaller ambulances (usually Ford chassis) using only 2 and the larger medium ambulances usually using 3-4 batteries.
Unfortunately, if you have one bad battery, you need to replace all of them to ensure that they are all alike. The Fire Chief's association recommends that they be replaced every year for in-service ambulances, but I assume that this stretched to a bit longer at times, particularly with a reserve ambulance. My batteries were replaced in 2013, so I should be able to get 4-5 years out of them if I keep them in good condition. Replacing a Group 31 battery runs about $ 125 or so per battery. I've kept my eyes open when I see them to see what the range seems to be, and $125 seems to be about what they cost. The battery manufacturer choice is wide open - SAMS club sells Energizer, and Interstate Batteries are available about anywhere through Batteries Plus, but I think my next batteries will be Alliance (http://alliancetruckparts.com/Catalogs/batteries/3?s=1001). I just found out about them a while ago - they are sold through truck dealers, such as Freightliner, and are designed for heavy duty use.
I'm also installing one more battery - a deep cycle battery that will be dedicated to the refrigerator, and possibly some added internal LED lighting. That way, I can leave the refrigerator running without worrying about running down the starting batteries. It will be charged with an Xantrex Echo Charge unit - this supplies up to 15 amps when the engine is running. I'll also add a dedicated 10 amp Xantrex charger to this battery as well for times when the ambulance is sitting and 120 volt power is available.
Any battery connections must be correctly done - don't try to get by with hardware store terminals - use marine terminals for battery connections. I use a hydraulic lugger on all the terminals I install.
Check the Blue Sea web site for cable sizing information - they will be larger than you thought you would need due to voltage drop. Most wire sizing charts are based on the total wire length - positive and negative must be added together. I have #2 cables running from my inverter to the batteries - this works since they are only 8 feet apart. I'm planning on my new DC panel having a load of no more than 40 amps, but I'm feeding it with #6 cable.
Ambulances use a stud terminal (3/8-16) to both simplify paralleling, and also connecting additional taps to the terminals.
All food for thought-
When you install a Riv-Nut, drill the right sized hole (it needs to be a clean, circular hole). I use a step drill to get it as close as possible, then a final pass with the exact drill specified. For instance, a 1/4" knurled Riv-Nut (McMaster 95105A143) requires a 25/64" hole. Since this is 1/64" larger than 3/8", I drill the initial hole to 3/8" with a step bit, then a final pass with a 25/64" bit. Once you drill the hole, you can see the hole thickness, and pick the right size Riv-Nut. I like to drill a trial hole in a chunk of scrap aluminum so I can verify that I have the right stroke set on the installation tool.
I've used Riv-Nuts on aluminum military radio shelters where there was no other way to install a screw - the shelters use a sandwich construction with an 0.050" aluminum inner layer bonded to 2" of urethane foam - they did the job perfectly.
On to batteries: I have the advantage that my battery installation was designed by Medic-Master/Freightliner. I have four Group 31 batteries in parallel for both engine start and to run the module when the engine isn't running. Since the module includes a lot of internal lighting (at about 5 amps per bulb) and external warning and scene lights, the ambulance has a 270 amp engine alternator. There is a test tag in the module that shows the actual power demand with everything operating (236 amps), and with optional equipment shut down (164 amps). Various ambulance designs use from 2-4 batteries, with the smaller ambulances (usually Ford chassis) using only 2 and the larger medium ambulances usually using 3-4 batteries.
Unfortunately, if you have one bad battery, you need to replace all of them to ensure that they are all alike. The Fire Chief's association recommends that they be replaced every year for in-service ambulances, but I assume that this stretched to a bit longer at times, particularly with a reserve ambulance. My batteries were replaced in 2013, so I should be able to get 4-5 years out of them if I keep them in good condition. Replacing a Group 31 battery runs about $ 125 or so per battery. I've kept my eyes open when I see them to see what the range seems to be, and $125 seems to be about what they cost. The battery manufacturer choice is wide open - SAMS club sells Energizer, and Interstate Batteries are available about anywhere through Batteries Plus, but I think my next batteries will be Alliance (http://alliancetruckparts.com/Catalogs/batteries/3?s=1001). I just found out about them a while ago - they are sold through truck dealers, such as Freightliner, and are designed for heavy duty use.
I'm also installing one more battery - a deep cycle battery that will be dedicated to the refrigerator, and possibly some added internal LED lighting. That way, I can leave the refrigerator running without worrying about running down the starting batteries. It will be charged with an Xantrex Echo Charge unit - this supplies up to 15 amps when the engine is running. I'll also add a dedicated 10 amp Xantrex charger to this battery as well for times when the ambulance is sitting and 120 volt power is available.
Any battery connections must be correctly done - don't try to get by with hardware store terminals - use marine terminals for battery connections. I use a hydraulic lugger on all the terminals I install.
Check the Blue Sea web site for cable sizing information - they will be larger than you thought you would need due to voltage drop. Most wire sizing charts are based on the total wire length - positive and negative must be added together. I have #2 cables running from my inverter to the batteries - this works since they are only 8 feet apart. I'm planning on my new DC panel having a load of no more than 40 amps, but I'm feeding it with #6 cable.
Ambulances use a stud terminal (3/8-16) to both simplify paralleling, and also connecting additional taps to the terminals.
All food for thought-
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patoz
Expedition Leader
That is some excellent information on the Riv-Nuts and tools. I have a Grainger about 5 miles from me, so I'll check with them about the Marson tools. That way I can see it before I buy it. Somewhere I saw a counter sunk Riv-Nut that would sit flush when installed, so that there is no gap between the mounting surface and what is being mounted. I'm considering using those (if I can find them again) to mount the panel(s) that will cover the front where I removed the cab. I need to have that cover removable so that I can retain access to the back of the existing electrical panel and AC/heat closet.
Good info on your battery setup also. It sounds like you're not planning on doing a whole lot of off-grid camping with just one deep cycle battery. Of course, you didn't say what size it will be, so it could be a monster!
In the past, I have used the type of ring terminals for battery connections that use a low temperature solder pellet to connect the terminal to the cable, and is then covered with heavy duty adhesive lined heat shrink. No crimping required. I have never had a failure or any kind of problem with this system, but I wonder if it's possible for this connection to get hot enough under some overload type situation, to become unsoldered? But then, that might be a good thing...if it got that hot, it would work like a fusible link and break the connection (or arc and cause a fire ). My panel came with a 100 amp DC main breaker, and I bought a Blue Sea 200 amp 187-Series Circuit Breaker which will be mounted right at the battery bank in the compartment, and also serve as an emergency disconnect device that will be accessible from the exterior of the unit. I went with the 200 amp breaker so I can power other high amp loads that may not go thru the panel like a winch, power jacks, etc.
AC System question - Are you planning on using a ELCI Main Circuit Breaker in your AC system? An ELCI, installed as required within 10’ of the shore power inlet, provides 30mA ground fault protection for the entire AC system beyond the ELCI. GFCIs are still required in heads, galleys, machinery spaces, and weather decks.
From what I'm reading, and considering Ambulance bodies are completely metal (although they are heavily painted) as compared to a fiberglass camper, it looks to me like we should. It's now required on all boats with AC Shore Power systems, but I don't know about campers and RVs. However, an ELCI should keep a person from being electrocuted if they touch the body of the ambulance while contacting the ground (earth) if the hot or neutral contacts the body at any point while plugged into shore power. Theoretically, the breaker on the camp ground power post should trip as soon as you plug in or the short occurs, if it's wired correctly and in good operating condition. But then we all know how well that stuff is kept up.
This article is primarily about grounding, but addresses the situation also. This is a UK based website, but the articles are well written and explain things in layman's language.
http://www.smartgauge.co.uk/earthing.html
Good info on your battery setup also. It sounds like you're not planning on doing a whole lot of off-grid camping with just one deep cycle battery. Of course, you didn't say what size it will be, so it could be a monster!
In the past, I have used the type of ring terminals for battery connections that use a low temperature solder pellet to connect the terminal to the cable, and is then covered with heavy duty adhesive lined heat shrink. No crimping required. I have never had a failure or any kind of problem with this system, but I wonder if it's possible for this connection to get hot enough under some overload type situation, to become unsoldered? But then, that might be a good thing...if it got that hot, it would work like a fusible link and break the connection (or arc and cause a fire
). My panel came with a 100 amp DC main breaker, and I bought a Blue Sea 200 amp 187-Series Circuit Breaker which will be mounted right at the battery bank in the compartment, and also serve as an emergency disconnect device that will be accessible from the exterior of the unit. I went with the 200 amp breaker so I can power other high amp loads that may not go thru the panel like a winch, power jacks, etc.AC System question - Are you planning on using a ELCI Main Circuit Breaker in your AC system? An ELCI, installed as required within 10’ of the shore power inlet, provides 30mA ground fault protection for the entire AC system beyond the ELCI. GFCIs are still required in heads, galleys, machinery spaces, and weather decks.
From what I'm reading, and considering Ambulance bodies are completely metal (although they are heavily painted) as compared to a fiberglass camper, it looks to me like we should. It's now required on all boats with AC Shore Power systems, but I don't know about campers and RVs. However, an ELCI should keep a person from being electrocuted if they touch the body of the ambulance while contacting the ground (earth) if the hot or neutral contacts the body at any point while plugged into shore power. Theoretically, the breaker on the camp ground power post should trip as soon as you plug in or the short occurs, if it's wired correctly and in good operating condition. But then we all know how well that stuff is kept up.
This article is primarily about grounding, but addresses the situation also. This is a UK based website, but the articles are well written and explain things in layman's language.
http://www.smartgauge.co.uk/earthing.html
rlrenz
Explorer
I think both Grainger and McMaster sell the same Riv-Nut tools, and they both ship at the speed of light. If you order from McM on a Monday, you should see the tool in a few days. Probably the best out there are made by Marson, and if you buy their tool, you can always buy mandrels for additional sizes of Riv-Nuts---lottsa luck with a Chinese tool. I have seen a Riv-Nut designed with a shallow angle on the head (probably about 118 degrees, like a countersunk pop-rivet), but they are mighty hard to find. If you need some 5/16-18 closed end countersunk/flush Riv-Nuts, I have a bunch that I picked up war surplus someplace, probably from Spruce Mountain Surplus up in the NE somewhere. If they would help, let me know, and I'll see how many are in the bin.
I'm not planning on living off the grid very far, and not for too long. I thought about adding a solar charger to the roof, but the prices are high enough that it dropped very far down on the list. As you may have learned by now, deep cycle batteries are mighty pricey if they have lots of amps in the piggy bank. One of my ambulance mechanic friends spoke highly of both Interstate and Exide deep cycle batteries (Alliance only offers a combined starting/house service battery). Interstate are available all over the place, and I found out that Exide are sold by Tractor Supply (only 5 miles from me). The boat stores also sell deep cycle batteries, but I've noticed that their prices are definitely retail. One possible alternative to 12 volt deep cycle would be a pair of 6 volt golf cart batteries in series - considering how many golf carts are out there, they should be available new at a very decent price, and might be worth picking up as used if the price is right and they aren't too old.
Regarding GFCIs and ELCI breakers - The GFCI is designed to trip at 5 mA of ground fault, while the ELCI breaker is designed to trip at 30 mA of ground fault. Instead of using one ELCI breaker for the entire module, I'm planning on using GFCI receptacles for every receptacle installation. I was able to pick up a supply of new hospital-rated GFCI 15 amp receptacles (with pilot lights) at a very nice price. I'm using red receptacles for receptacles that are supplied by the 1000 watt Vanner inverter, and white GFCI receptacles for locations supplied from shore power or the generator - that way, anyone riding in the module can connect the the appropriate receptacle. Since the inverter is rated at 1000 watts, I have to plan accordingly - for example, my wife likes a Kurig coffee maker, but the regular Kurig makers pull about 1500 watts. In order to permit operation while under way, I'll buy the Kurig designed for hotel rooms since it only pulls 750 watts.
I'm not planning on living off the grid very far, and not for too long. I thought about adding a solar charger to the roof, but the prices are high enough that it dropped very far down on the list. As you may have learned by now, deep cycle batteries are mighty pricey if they have lots of amps in the piggy bank. One of my ambulance mechanic friends spoke highly of both Interstate and Exide deep cycle batteries (Alliance only offers a combined starting/house service battery). Interstate are available all over the place, and I found out that Exide are sold by Tractor Supply (only 5 miles from me). The boat stores also sell deep cycle batteries, but I've noticed that their prices are definitely retail. One possible alternative to 12 volt deep cycle would be a pair of 6 volt golf cart batteries in series - considering how many golf carts are out there, they should be available new at a very decent price, and might be worth picking up as used if the price is right and they aren't too old.
Regarding GFCIs and ELCI breakers - The GFCI is designed to trip at 5 mA of ground fault, while the ELCI breaker is designed to trip at 30 mA of ground fault. Instead of using one ELCI breaker for the entire module, I'm planning on using GFCI receptacles for every receptacle installation. I was able to pick up a supply of new hospital-rated GFCI 15 amp receptacles (with pilot lights) at a very nice price. I'm using red receptacles for receptacles that are supplied by the 1000 watt Vanner inverter, and white GFCI receptacles for locations supplied from shore power or the generator - that way, anyone riding in the module can connect the the appropriate receptacle. Since the inverter is rated at 1000 watts, I have to plan accordingly - for example, my wife likes a Kurig coffee maker, but the regular Kurig makers pull about 1500 watts. In order to permit operation while under way, I'll buy the Kurig designed for hotel rooms since it only pulls 750 watts.
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rlrenz
Explorer
By the way - if you REALLY want to be different, you can buy a 12 volt microwave. The 'wave itself doesn't run on 12 volts - it has a built-in inverter, and it needs some pretty heavy duty power cables to make it all run. I had thought about one, but it would be a total oddball, and if it ever pooped out on the road, it would be impossible to replace. I had thought about buying a microwave that could live on my Vanner inverter's 1000 watt output, but that would limit me to about a 600 watt microwave (college dorm sized) since microwaves pull about 1.5 X their rated output for input power). I'm not sure how much microwave use I should plan for while on the road - it might be a lot safer to limit the microwave to while-stopped in a rest stop or at the end of the day, plus I'm not thrilled about trying to eat a bowl of chili at 65 MPH. If I plan on operation only while stopped, then I have the generator or shore power to support a larger microwave, and that sounds like about the best solution.
My wife's coffee pot doesn't worry me - a Kurig is small enough that it can sit adjacent to the sink on a piece of anti-skid mat (Sears tool box drawer liner), and if I have to, I can rig up a suction cup hold down for the K.
My wife's coffee pot doesn't worry me - a Kurig is small enough that it can sit adjacent to the sink on a piece of anti-skid mat (Sears tool box drawer liner), and if I have to, I can rig up a suction cup hold down for the K.
patoz
Expedition Leader
The 5/16-18 would work fine. Once I get a design for the panel(s) and source the metal, I'll let you know, Thanks for the offer!
Yeah, I priced several different manufacturers and types of batteries, and they are all expensive for a quality product. I finally decided on two 6V Trojan T-105 Deep-Cycle Flooded batteries. I have a custom golf cart dealer about 2 miles away and got them for $137.00 each. If that doesn't do it, I'll add two more.
I won't be doing much off-grid camping either, but I'm taking into consideration a disaster type situation, i.e. a Cat 5 hurricane (or Zombie attack) and having to evacuate. I'm NOT going to any shelter, and finding a motel along any evac route is usually almost impossible, especially at the last minute, so I may end up in a Wal-Mart parking lot or some place like that where running a generator may not be the best thing to do. Solar is on my list also, but way down the list.
That sounds like a good plan, and especially if you already have the outlets. However, the outlets only protect what's plugged into them or what's wired downstream, and won't provide protection for the body of the vehicle in the event of a system wiring problem or short. At least that's the way I understand it.
I have a small Kurig also, and will probably just move it from the kitchen to the camper when I need to.
The 12V microwave sounds cool, but as you say replacement time could be a real pain. I'm going to have one, but it will just be for warming food up or maybe boiling a cup of water, of course the Kurig will do that also.
rlrenz
Explorer
I'll take a photo of that they look like and post it.
That's the same Trojan battery I was thinking about, and the price is definitely nice - take a look at what the marine dealers get for a 12 volt deep cycle for a real pucker-factor price.
Here in MN, there aren't many hurricanes to worry about, but they have to be a factor in your planning. I imaging an entire state looking for a motel room could cause a challenge... The idea of having a very durable RV available that probably won't be blown over easily makes a lot of sense.
I've had the same questions and thoughts about protecting the entire vehicle's 120 VAC wiring, but right now, the Vanner inverter only supplies 3 locations. When I install my new system, all the existing 120 volt wiring will be replaced with marine triplex cable (Amazon, where else?). The cable is in a sheath, similar to Romex house wire, plus it will be run in convoluted tubing, so I'm not too worried about physical damage to the wiring. AN ELCI breaker is a thought, though.
That's the same Trojan battery I was thinking about, and the price is definitely nice - take a look at what the marine dealers get for a 12 volt deep cycle for a real pucker-factor price.
Here in MN, there aren't many hurricanes to worry about, but they have to be a factor in your planning. I imaging an entire state looking for a motel room could cause a challenge... The idea of having a very durable RV available that probably won't be blown over easily makes a lot of sense.
I've had the same questions and thoughts about protecting the entire vehicle's 120 VAC wiring, but right now, the Vanner inverter only supplies 3 locations. When I install my new system, all the existing 120 volt wiring will be replaced with marine triplex cable (Amazon, where else?). The cable is in a sheath, similar to Romex house wire, plus it will be run in convoluted tubing, so I'm not too worried about physical damage to the wiring. AN ELCI breaker is a thought, though.
rlrenz
Explorer
I only have about 25 of the 5/16" Riv-Nuts left. They are about a 100 degree head angle (similar to a flat head machine screw for thin material), and they are also stainless steel, so they may not be what you are looking for. I'm sure I found them as MIL surplus. Their overall length is slightly more than 1", so it's anyone's guess what thickness of parent material they are designed for. I'll try to get a photo in the next day or so.
A regular Riv-Nut has a thin lip and only sticks about 0.020/0.040" above the surface if you're worried about installed height.
A regular Riv-Nut has a thin lip and only sticks about 0.020/0.040" above the surface if you're worried about installed height.
patoz
Expedition Leader
Stainless would be fine, especially since I will be using stainless screws, but 25 would be cutting it real close. The length would probably be OK going through the skin and into the 2" x 2" square tube framing, but might be too much for just the skin.
I've been on the Marson page looking at what's available, and since the lip for 1/4-20 is only .028, it probably won't be a problem. I will need to put some very thin weather stripping or gasket material between the two, and it will probably be thicker than the lip anyway.
I've been on the Marson page looking at what's available, and since the lip for 1/4-20 is only .028, it probably won't be a problem. I will need to put some very thin weather stripping or gasket material between the two, and it will probably be thicker than the lip anyway.
rlrenz
Explorer
I usually buy self adhesive foam from McMaster, and about all you should need is 1/16" foam. Just be careful to drill a precise hole - I start with a step bit (Versa Bit), then take a final pass with a exact size bit. Use a new bit, and be careful deburring the holes - I use a machinist's blade-type deburring tool. and about all it takes is one pass. I recommend only the knurled/heavy duty Riv-Nuts, and try one in a scrap hunk of aluminum to be sure your settings are right. The instructions for the Marson tool can drive you nuts - they are very poorly written. If you want, I can e-mail you a scanned copy. Also, don't try to save some bucks on cheap Riv-Nuts - I wound up with some that have very poor threads - they will pull out before the Riv-Nut expands - I've never had this problem with knurled nuts, just smooth shank nuts.
Google it Research
Master of Disaster
Tagging along for the build.
rlrenz
Explorer
Welcome aboard.
Most folks rebuilding ambulances into RVs/expedition vehicles usually pick a used smaller ambulance, with nearly all of them being Fords. There are a few of us who want a larger vehicle for various reasons, such as towing a larger trailer. Me? I like a truck, I like the room, and many years ago, I used to rebuild Army trucks for fun, so my garage will swallow a Freightliner ambulance without a burp. My garage door is 10' high, and my ambulance is 9'-6". Length will be a little tighter than with the Army trucks, but once I move a garage air compressor and chop about half of the rear bumper off, it'll fit with walking room around the whole thing.
The other advantage is that I can easily find room for propane tanks, a generator, water tanks, and all the rest.