Advice on Mounting Diesel compressor on Tandem Trailer.

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Guys,I am planning on mounting a diesel compressor on a Tandem trailer for my mobile Soda Blasting Business. I will remove the axle & drawbar from the compressor. Compressor weights around 2600 lbs & blast pot weights 420 lbs.Trailer is supposedly rated for 7000 lbs, (2 3500 lbs axle). I am not sure how they rate these.Attached are a few pics, 1 of them shows how a diesel compressor is being mounted on a tandem. Trailer Specs:2- 3500 LBS axlePintleBrakes on Both axlesSide Gate12' Deck over trailer, around 1200 lbs.Blasting pot weights around 420 lbs.I plan to have atleast 3200 LBS of equipment on the trailer without any blast media. I also have my bed of my pickup. (2500 Ram Diesel) I will not attempt this setup, however, i would like to know the best possible solution so i can be sure who ever will be doing the job will do it right.Questions:1) How would you mount the compressor to the trailer?2) Ive posted a few pics of the trailer, do you think it was built stong enough to handle the weight?3) All Comments welcomeThanksRich Attached Images
Reply:Anyone?
Reply:I would be inclined to bolt things down.  I have seen people weld things to a deck.  They are not popular when it comes time to move or service equipment.  I would make up small plates say 3/8 thick with a hole in the center and a nut tacked on.  Set your units in position then drill or blow holes through the deck.  Run your bolts through the equipment frame and set your nut plate under the deck.  Tighten up then tack weld the nut plate to the underside.  Now you will not have to hold nuts with a wrench under the deck when it comes time to remove.  It sure would not hurt to use Never Sieze or some other type of anti-sieze material.
Reply:Well the trailer should handle that with no problem.    I would bolt it thru the floor and cross members to the trailer.  Even if a frame has to be built to mount the compressor on,  I would bolt it to the trailer.  Not just attach it to the floor sheet.  After a while the vibrations, and forces will pull the bolts thru or welds will break due to the flexing of the floor.  This may require welding in some under floor supports between the cross members. it really won;t matter how you arrange the pieces as long as you have the weight distributed with it slightly heavier on the tongue in order for it to track well behind the truck.I'm a Lover, Fighter, Wild horse Rider, and a pretty good welding man......
Reply:Where you place the load impacts the tongue weight.  You should have 10-15% of the total trailer weight on the tongue including the weight of the trailer.  Add up the empty trailer weight, weight of the compressor, a full tank of fuel for it, pot, any related equipment, and a typical load of media and then calculate the percentage for the tongue weight.The weight rating of the trailer includes the weight of the trailer.  Subtract the empty weight of the trailer from 7000 and that will give you the weight of the cargo you can haul.  The axle ratings are the maximum weight the individual axle can handle.  Brakes on both axles are a good thing  There should be something in your truck's owner's manual about the total weight the truck can tow.  The local Dodge dealer can povide that for you.  Try not to exceed 85% of the maximum towing weight for best handling, braking and performance.  With the trailer fully loaded, it will tow best if the trailer is level and the truck is not too low in the back.  Helper springs or air bags can help keep the truck level.  The compressor should probably be centered over the axles if possible and then place the rest of the equipment to the front and back.  Bolting everything down is a good suggestion. You may have to remove stuff at some point and it makes it easier to unbolt things compared to cutting off welded brackets.Don't forget a good trailer brake controller.  I use a Prodigy controller on my truck for my car trailer.  Simple plug and play install and you can get a ready-made harness for your truck so you don't have to cut wires.
Reply:Not trying to cause a fuss, but I have never had as much as 10% of total weight on a tongue of any trailer I built.  If the trailer loaded weighs in at 7000lbs You will need 700 lbs or more down weight on the tongue?  That seems mighty excessive.  I personally have never seen a trailer that needed near that amount of weight to track properly.I'm a Lover, Fighter, Wild horse Rider, and a pretty good welding man......
Reply:Thanks for the Reply lotechman:Im guessing we are making the nut flush with the plate on 1 side so that the plate acts a a big washer correct? In this case, we are bolting to the floor, will the floor hold up to this?Hammack_WeldingIf I were to build a frame, im assuming it would out of sqaure tubing right? Now if we build this frame, you are saying to bolt this frame to the crossmembers.... How do we attach the compressor to this frame? Blow/drill holes from the compressors frame to the new frame on deck and bolt to that? If so, Do we bolt all the way to the crossmemebers or just the frame above? c4cruiser1) Truck is rated for 12k tow and 2250 Payload. I think I am ok with this department. 2) I am was aiming to place the compressor directly on the back, not necessarily centered over the 2 axes, but when using 10-15 on tongue, it works out fine. 3) What is the purpose of the brake controler? I think my truck is already prewired for brakes. When i towed the trailer, i could feel the brakes already. My truck has a 5 port plug in the rear and diagram shows brakes. I could always play with the tongue, so i am not too worried about that.Sorry for not being knowlegable in this field, i dont have the slightest clue about fabrication or welding, well i do, but im not sure if it makes sense.
Reply:3) What is the purpose of the brake controler? I think my truck is already prewired for brakes. When i towed the trailer, i could feel the brakes already. My truck has a 5 port plug in the rear and diagram shows brakes.
Reply:I could always play with the tongue, so i am not too worried about that.
Reply:1200 LBS trailer weight2600 LBS Compressor420 LBS pot weight100 Aftercooler & drain setup100 for MISC. hoses 4420 Total x 15% = 443The Blast Pot itself weights 420 which will be place all the way upfront side the side gate is all the way upfront. That leaves me with 243 lbs which is no problem at all..
Reply:The problem is mounting the compressor I havent factored in media weight, but atleast we can have an idea.
Reply:Is this compressor on a frame of its own that is bolted to the existing trailer frame or are they integral to each other? I won't even pretend to say how to mount it but will throw in thing or two for consideration. One would be maintenance issues like oil changes and such. Where is the drain plug, things like that. Airflow through the radiator and across the engine in proximaty to other components. Cleaning in, out and from under the beast. These may influence the how to part.
Reply:Originally Posted by SandyIs this compressor on a frame of its own that is bolted to the existing trailer frame or are they integral to each other? I won't even pretend to say how to mount it but will throw in thing or two for consideration. One would be maintenance issues like oil changes and such. Where is the drain plug, things like that. Airflow through the radiator and across the engine in proximaty to other components. Cleaning in, out and from under the beast. These may influence the how to part.
Reply:take a look at my 4th pic
Reply:My suggestion about nut plates is to limit crawling uner.... hammack's idea of using frame members is better than just the deck plate.   I am not sure about how much vibration you are going to get on the deck.  If it would be a problem than a sub frame with some sort of vibration isolators would be required.  draining oil:  A  good trick  I learned form having to service marine engines is to plumb a hydraulic hose to the crankcase drain plug.  Have it long enough that it can be run up the side of the engine and zip tied in place.  Use a standard plug on the end.  When you are ready to change oil just cut the zip tie, undo the plug and lower the hose into your drain pan alongside the engine.
Reply:SandyIn that pic, it looks like they used a piece of sqaure tubing with a plate welded on the sides. The plates lines up with the trailer stock axle brackets and just bolts through. I could be wrong, but doesnt make sense?Because of the width of my compressor and trailer, i have to place it horizontal. Someone else has suggested plumbing the drain plug, which isnt a bad idea at all. Im thinking just to just a hole in the deck. This is deck over trailer, thus higher off the ground, i could fit under there easily. I just hope the
Reply:Here are some additional pics of the compressor Attached Images
Reply:anyone?
Reply:I guess not...