I Bought a $500 Trailer for my Mobile Sauna but had to Completely Rebuild it

Since my last post I decided to throw in the towel on trying to build an under-2,000-pound mobile sauna an SUV can pull. YOLO!

I’m building a full-sized 8×12 mobile sauna with a changing room. Being over 4,000 pounds I’ll need a pickup truck to pull it. I’ll rent a pickup truck a few times first to see how it feels. If I love the mobile sauna life I’ll trade in my trusty, beat-up Nissan Altima for a pickup.

As I studied how to approach and build a mobile sauna, my friend and sauna sensai Matt told me to just start with a trailer. I looked at buying a brand new trailer but given the $4,000 budget my wife and I agreed on I thought maybe I could save some money with a used trailer.

After scouring craigslist and Facebook marketplace daily for a few weeks, a 6×10 trailer popped up about 25 minutes from me for $500. My dad and I made the trek to have a look, in separate vehicles and wearing masks with covid still roaring. We were happy to discover all of the bolts were stainless and the entire body was aluminum which saves 400-500 pounds vs. a steel trailer. The tires were in obvious disrepair but everything else looked solid. There was no rot on the axles or anything overly concerning. I signed the P&L for the fair asking price of $500.

We jacked the trailer up and removed the two rear wheels, figuring we can make it home on 2/4 new tires. I ordered two trailer tires and had them mounted locally for about $200. The next day we rented a pickup truck and to our surprise when we plugged in the trailer lights and they actually worked!

Al Cook, the oldest living Cook, circa 1953

Luckily the ride home was smooth and uneventful yet in the following weeks I realized something: Pretty much the entire trailer had to be rebuilt.

Homemade trailers can be Frankenstein. This trailer seems like it’s made from repurposed highway guardrails (all aluminum, which is a huge plus), two different sets of wheels from two different 1970s Volkswagon Rabbits, and the axles had no markings.

Trailer axle capacity can be estimated by removing a wheel and the underlying hub and taking a measurement with a depth caliper. My axles measured at just under 1″.

After reaching out to 5 different axle manufacturers I learned 1″ axles vary widely: 480 – 2,000 pounds depending on who makes them. The most common is 1,000 pounds with 2,000 pounds being a rare bird featuring markings my axles lacked. Some good news, though: On getting the trailer home we realized it’s 6×12 not 6×10 as the previous owner thought — big enough for a full sized 8×12 sauna!

Being a civil engineer, safety is my wife’s thing. The last thing I want to do is roll down the highway and have a catastrophic failure with her as culpable passenger. I ordered:

  • 2 new axles rated 3,500 pounds each (total 7,000 pound capacity)
  • 4 new leaf springs rated 1,750 pounds each (total 7,000 pound capacity)
  • 4 new wheels rated 1,666 pounds each (total 6,664 pound capacity)
  • 4 new tires rated 1,360 pounds each (total 5,440 pound capacity)

The trailer capacity is 5,440 pounds with the tires as the weakest link. After ordering these parts for $1,323 I found out the guy who made the trailer used an obscure, custom spacing between the old leaf springs. I brought my brand new axles to a local welding shop who moved the plates on the axles in by 4″ for $200.

Growing up my dad ran a landscape contracting business and still owns his skid steer. He offered to flip the trailer over to make it easier to install all the new parts.

My dad and I in his Bobcat skid steer circa late 1980s

Over a couple afternoons, I put on my Trailer Rebuild Guy hat and got to work. I removed all the old hardware, installed the new axles and leaf springs, packed bearings with grease by hand, and installed the 4 new wheels.

The trailer flipped over and partially rebuilt; My brother Adam is a free agent junkyard model
Completely rebuilt.
Ready to haul materials!

I’m not surprised I’m in this trailer for $2,223 which is far more than the too-good-to-be-true $500 I paid. I haven’t started building anything and I’ve already blown just over half of the $4,000 budget my wife and I set. But I got an education on how trailers are made, I’m more confident the wheels won’t fall off while rolling down the highway, and if they do I’ll know how to put them back on! Now I just have to figure out how to build an 8×12 sauna for under $1,800 with lumber prices at record highs.

Designing a Mobile Sauna Under 2,000 Pounds

In recent years mobile saunas have picked up steam. Recently this post on Reddit really sucked me in. Living south of Boston with so many great beaches, kettle ponds, and lakes I can’t help but scrap all my ideas for a sauna building and go deep on mobile.

Our first month of the year “January” dip into the lake and another adventure with my wood burning mobile sauna!
/u/Sauna_Scarlet

A few weeks ago I was scoping out the true cost of an 8×12 sauna building (on land, not a trailer) using the Sauna Times plans. At the time I quickly looked at what it would cost to make it mobile and with large enough trailers being $3,000 or more, I let it go. But by downsizing from 8×12 to say 5×8 or 6×10 the cost of the trailer drops to about a third.

After some digging around it looks like Tractor Supply is the best place for trailers near me. They deliver them free to your local store and there’s one half an hour from me. They’ve got a 5×8 trailer for $899 and 6×10 for $999.

At first I was wishfully thinking I could build a sauna-and-changing-room-combo building but weight is a huge constraint unless you have a legit truck. My wife and I have a Jeep Wranger and RAV4 Hybrid. Both vehicles max out at about 2,000 pounds tow capacity. The Rav’s official tow capacity is 1,750 but this Youtuber had good luck going through mountains with a 2,000 pound load. For a few moments I entertained getting a(n also tiny) pick up truck but it’d be a little too crazy to get a truck specifically for sauna.

This 4×4 Ford Ranger from ’99 towing a dark green sauna would look mint. If it’s got the tow package it can handle a load just under 6k pounds. $3,400.

With loads of optimism I fired up Google Sheets, thinking for sure I can build a 6×12 sauna with a changing room on one of these tiny trailers. Using this handy wood species calculator and weight details from product pages, I came up with some early estimates. It looked like a 6×12 build would be about 2,500 pounds. With my poor estimation skills it’s probably more like 3,000. I tweaked the sheet to allow for experimenting with various dimensions.

I realized I can’t go any bigger than 6×9 which means no changing room. It’ll have to be the car or a pop-up shower tent!

Assumptions and iffy bits:

  • I’ll use clear tongue & groove white pine on the inside. It’s local, it’s cheap ($1.20 per SF), and I’m looking to do this build on a low budget.
  • I’m guessing removing the trailer gate saves me 200 pounds.
  • I haven’t quite finalized the floors but given the trailer itself has a deck I doubt I’ll put in a full platform with 2×6 rafters and all. This is missing from the cost and weight estimates. I wonder if I can get away an uninsulated floor and basically bolt 1/2″ plywood on top of the trailer deck, covered in cement board.
  • LP SmartSide panel is the lightest siding after vinyl, looks decent, and lasts a while. I’d love to use local rough-cut pine but makes my siding almost 600 pounds vs 400. Plus the rough cut pine is likely to be green and even heavier.
  • I’ve no idea about the cost and weight of the roofing.
  • I’m using seagrass for insulation and the weight at 100 pounds is a wild guess.
  • I haven’t built in the weight of the door, windows, hardware, bolts for securing the building to the trailer, nails and probably a few other things.

I’ll probably end up shooting for 6×8. Even that’s a stretch at an estimated 2,133 pounds.

I’m tempted to follow my buddy Sauna Matt’s advice from a phone call this morning: Buy the trailer and get started. Maybe I’ll end up in that red pickup after all.

The estimates are easiest to to see in Google Docs. You’re welcome to grab a copy and play with it by going to File > Make a Copy.

I’m Insulating My Sauna with Seagrass

My cousin Spencer is a Native American and one of my favorite people on earth. Thanks to Spencer, I learned about eelgrass a couple years ago and lately I’ve been thinking about insulating my sauna with it. Sure, it’ll only save me about $300 and I’ll have to work for it but it’ll be a good conversation starter.

Spencer lives on tribal lands along the coast of Massachusetts. He has many outdoor passions like foraging and gardening. One day a tribe elder approached him to pass along knowledge of a seaweed called eelgrass. He told Spencer to go to the beach, collect eelgrass washed up on the shore, and apply a 6-10″ layer to his garden bed like mulch. Spencer was skeptical at first yet after some experimenting he became an eelgrass convert. Eelgrass releases nutrients into the soil to help plants grow better. More importantly to Spencer it acts like a sponge, slowly releasing water into the soil and allows gardeners to water less.

Recently, I started learning more about eelgrass. Sure, it’s great for gardening, but it turns out it also cleans ocean water, reduces erosion, and provides habitat for creatures. (A great study on eelgrass in Massachusetts.) One of the most fascinating facts about eelgrass is it was used as insulation for hundreds of years in America before fiberglass was invented.

Live eelgrass on the ocean floor
Photo credit @theclf

In the early 1900s, entrepreneur Samuel Cobalt noticed huge mounds of seaweed washed up on beaches in the Boston area. After exploring potential uses, he learned houses going back to the 1600s and earlier used this seagrass known as eelgrass for insulation. It turns out eelgrass has a high concentration of silicon which makes it great for retaining heat and deadening sound while also being fire and rot resistent.

Eelgrass is also sustainable as only dead material is used. It naturally separates from the roots in the ocean floor and floats to the surface. Cabot launched Cabot’s Quilt, gathering large quantities of eelgrass to process it into insulation, complete with a paper lining and everything.

Build Warm Houses — That is the only way to cheat the devouring demon in your cellar who burns your money and poisons you with gas!

Shortly after Cabot’s Quilt launched, eelgrass suffered a blight in the 1920s which forced the company to turn turn to importing eelgrass from overseas. Still, the company did well for decades. Amazingly Radio City Music Hall is insulated with eelgrass and renowned for its acoustics. When fiberglass took off in the 50s it was the begininning of the end. Cabot lives on, offering wood stains.

Modern studies are being done on eelgrass in the Boston area where stocks have dropped 58% since the 1950s. It’s unlikely Cabot’s Quilt would’ve survived even if fiberglass wasn’t invented. Scientists don’t really know the cause of the continued drop since the 50s. Luckily there’s still enough eelgrass washing up on the shores to keep my little sauna toasty.

From the Massachusetts MarhineFisheries study on eelgrass, studying Plymouth Estuary located south of Boston MA USA. In 1950 there were an estimated 3,500 acres of eelgrass. By 2012, less than 1,000 acres remained representing a 58% population loss. A 2014 survey shows further widespread loss. Studies are due to resume after the pandemic.

The Saunas in New England are Closed so I’ll Build One

I just got back from a quick trip to New Hampshire for some winter hiking and, of course, wood-fired sauna.

For the first time in a while I felt a profound physical and mental calmness which carried through the days to an insanely deep night’s rest. (Slept 11 hours after the hike!)

I recently stumbled on this awesome mini documentary on Finnish sauna culture featuring these words describing sauna well:

A profound feeling of presence. The feeling after having a sauna… as they say is like after mediation, you have an inner smile. I feel that it has a healthy effect, that positively that comes with it. The process is mystical, you can’t really put into words, you have to experience it.

I mean, I guess it could’ve also been the near-perfect winter hiking that had me feeling good. Or combination of winter hiking and sauna. Or just spending so much needed offline time with my wife. I’m the king of life experiments with too many variables!

Back at home and wanting to ride this wave of calm for a while, I vigorously Googled for any open authentic saunas in the Boston area. (None of that infrared garbage.) The cabin I visited is incredible but being a 2-hour drive each way it won’t work as for weekly sauna, the schedule most enthusiasts use.

My favorite semi-public sauna in the area, Finland Steam Baths, is closed due to the pandemic. UKTS in Pembroke, New England’s oldest public sauna and one of my favorite places on earth, is closed too.

I found the Russian Sauna at Fire & Ice in Dedham, surprised I hadn’t heard of it until now. They offer online booking and look wide open for appointments. I sent them a quick email asking about pandemic procedures. A few days went by and I still hadn’t heard back.

My wife’s headed out to help with her niblings (you just learned a new thing: Niblings is the better way to refer to nieces & nephews) later this week. Thinking maybe the Russian Sauna isn’t all that into email, I gave them a buzz just now to try and squeeze in a last-minute booking.

On hearing that classic 3-tone “this line has been disconnected” message I went from completely amped to deflated. Yet I hang on. I know I’ll find weekly sauna somewhere.

As far as I can see, my closest option at this point for sauna during the pandemic (less the awesome little Airbnb in New Hampshire) is Nurture through Nature up near Portland Maine. They offer wood-fired sauna by the hour with an optional overnight cabin stay. Being a solid 3-hour drive, that’s not a weekly trip I can make and at this point there’s only one path: It’s time to build my own sauna.

All that’s left is convincing my wife.

The solar powered cabin and wood-fired sauna we rented on Airbnb.
The rear of the sauna in full swing
We pinned it a couple times.
The morning views out the cabin’s triangle window are spectacular.
The ladle handle my father-in-law built for me and my wife gave me as a combination Christmas/birthday gift this year. We picked up the spoon at a yard sale; full story for another post.
Sauna portraits!
An amazing day at Mount Chocorua.
Spectacular views