Meet our new bus... Mr. Beefy!

[TheHubbardBus]

A few pics from where we are now and where we hope to end up.
Interior is all clean and ready for upper painting. (first pic is a actually before ospho on ceiling.. so.. no more rust now)
Furniture colors are not correct... but you get the idea ;)

[Big Tim]

looks great!

[plfking]

That will be a nice, clean layout. I especially like that back door.

[Sevier]

Originally Posted by TheHubbardBus

After sweating out the last two months of summer, we're happy to report further forward progress! Namely, prepping, painting, & sealing the floor.

Before stopping due to heat, we had done some preliminary prep to tide us over & prevent further corrosion... angle grinder w/ wire wheels to knock down the worst areas in terms of rust, followed by a liberal application of ospho which we allowed to sit & dry.

Once the temps & humidity hit a happy range for paint, we reapplied ospho & allowed it to sit for a bit, then blasted it out with a power washer in order to completely neutralize it (failure to get all the ospho up could cause adhesion issues). Next was sanding (orbital w/ 80-grit followed by 220), power-washed again, applied a water-based cleaner/degreaser, power-washed a third time, & then dried thoroughly. In the end the floor itself was down to bare metal (or ospho-converted rust), while the fenders were a mix of clean/etched bare metal & prepped oem paint.

For the paint, we chose KBS Rust Seal, a water-cured high-solids urethane similar to POR15. Much of the prep done above was as per their requirements (though we didn't use their versions of cleaner or phosphoric acid). One cool thing about this product is you can use it along with fiberglass mesh to repair small holes, so we decided to go this route to seal the floor and patch all screw / bolt holes in the floor all at the same time.

After cutting more squares of fiberglass mesh than I can count, we laid down the first layer of KBS via foam brush to only the seams and areas surrounding the holes, pressing the fiberglass mesh patches into the paint as we went. After that cured enough to apply the first 'real' coat, we used a combination of foam brushes and low-knap (more like no-knap) foam rollers to paint as you'd expect. KBS recommended thinning 10% for rolling, which we did, & that was pretty much dead-on advice. You want to put it on as thin as possible, which is still way thicker than you expect.

Not counting the first coat on seams & holes, we put down 4 coats total, allowing to cure ~ 6 hours between coats. The less humidity the longer the cure, so in our dry climate it took some time. So yeah... it took us a good 24-hours to do the job, including waking up @ midnight for one coat. Even with the fan providing ventilation, we used half-mask respirators with new organic vapor cartridges, and are very glad we did, based on a couple times when my mask shifted. Painters booties & nitril gloves kept us from getting oil/dirt on our work as we went.

As far as KBS Rust Seal goes, their customer service is OUT OF THIS WORLD. I asked countless questions both before & after purchase, & their responses were extremely prompt, well-detailed, and dead-on accurate. As for the product, I couldn't be happier. The fiberglass patches worked great, and the paint itself looks to be pretty much indestructible. Adhesion appears to be excellent on everything, including the oem paint on the fenders/sides.

For those interested, for our 6-window short bus, each coat required 48 oz (1 qt + 1 pint). We bought both quart & pint containers so we didn't have to worry about resealing them between coats (which can be problematic). Each coat we just used up everything in the cans, then threw them away along with the foam brushes & roller pads. New brushes & pads for each coat.

The pics aren't show-car pretty (there was significant pitting / scale in spots, not enough to significantly weaken the metal, but enough to uglify it plenty), but our goal has been achieved: An impermeable sub-floor that will rust no further. This will all be under foam insulation & plywood in the near future anyway.

Hello there - youre descriptions of floor prep are so helpful (i\I've tracked them down through multiple threads). Was wondering if you could give a little clarity on the metal prep? We know to clean with degreaser, then use wire brushed to clean off all the rust, then we have the "Klean Strip" metal prep, and know to spray it on with a bug sprayer. This is like "ospho". So, do we let it fully dry, then wipe off with a damp rag? Or dont let it dry, and wipe off with a damp rag? Or leave it to help the primer adhere?

We plan on painting with primer right away after prepping, wont leave it for days or weeks.

Thanks and so sorry to ask a question with an answer that may seem obvious to others!

[TheHubbardBus]

Originally Posted by Sevier

Hello there - youre descriptions of floor prep are so helpful (i\I've tracked them down through multiple threads). Was wondering if you could give a little clarity on the metal prep? We know to clean with degreaser, then use wire brushed to clean off all the rust, then we have the "Klean Strip" metal prep, and know to spray it on with a bug sprayer. This is like "ospho". So, do we let it fully dry, then wipe off with a damp rag? Or dont let it dry, and wipe off with a damp rag? Or leave it to help the primer adhere?

We plan on painting with primer right away after prepping, wont leave it for days or weeks.

@Sevier,

Apologies for the late response. Been absent from forums as of late. I'll shoot you a PM to make sure you see this post.

Yes, degrease and thoroughly clean bare metal, then mechanically abrade. Definitely clean / degrease before or you'll just drive contaminates into the 'pores' of the metal you're creating.

We used both a wire wheel / angle grinder on the well-rusted / flaky / scaled areas, as well as an orbital sander on anything that was still relatively flat. The better you do here the better the adhesion. Just because the ospho will etch the metal doesn't mean thorough mechanical prep isn't much better than ospho alone. Just because they say you don't have to doesn't mean it isn't a really good idea to. We left zero bare metal untouched by grinder or sander.

Lots of controversy & differing opinions on the necessity of removing all ospho, and to an extent it depends on the paint you're using. But no matter what you're using, residual ospho will NOT help anything adhere, and from all the info I've gathered, could very well lead to paint failure. The safest bet is to let it do it's work (it needs to stay wet while working, so don't let it evap.), and then rinse every bit of it away thoroughly with water and get the surface bone dry before priming. A power washer is REALLY helpful here, assuming your bus is gutted to the point you can. Here's the owner of SPI (paint manufacturer) laying down the law, which is the advice I followed, & I'm glad I did.

How to neutralize Ospho | Southern Polyurethanes Forum

FYI, the Klean-Strip ospho you have is exactly what we used, and the MSDS shows it to be pretty much the same composition as ospho-branded phosphoric acid.

I'm actually well-positioned now to comment on the long-term durability of our KBS-coated interior floor, which most people probably don't get the opportunity to do as they often put their wood flooring and/or insulation down right after. COULDN'T BE HAPPIER. We've now been working for months on that floor - which is not yet covered. Sliding bare-metal ladders around, dropping heavy tools, drips & spills from various cleaners & solvents, etc. Constant under-foot flexing (I'm 260#) of weakened areas where rust was heaviest. Yet zero signs of delamination or lifting, and even the 'worst' scratches from the most careless boo-boos (like dropping claw hammers & drills from 6' height) could be buffed out if I cared to. The combination of flexibility + durability is outstanding. When we finally get wood over the top, I'm confident the underlying metal will be protected from further corrosion for years & years to come.

Finally, don't do the fiberglass mesh thing we did. It works - and it's really cool to see just how durable these patches + paint are - but I see now in retrospect it's unnecessarily labor-intensive, and it's easy to leave small voids that require touch-up later. The pennies / construction adhesive bit most people do makes a lot more sense. Sometimes creative solutions are a bad thing lol.

TL;DR:

1) Clean & Degrease thoroughly with water-based cleaner (Simple Green, TSP / TSP sub, etc) and abrasive scrub pads
2) Rinse thoroughly then dry
3) Mechanical abrasion (wire wheel, sanding)
4) Apply ospho liberally, keep wet (by adding more if needed) the entire time until ready to rinse (15-30 mins)
5) Rinse thoroughly, Dry thoroughly
6) Primer / Paint

[TheHubbardBus]

We've been absent from the forums for a while. I'm happy to report it was mostly due to getting stuff done! Lots of progress made, so here's a summary of the past few months:


First, we got the interior paint completed. Our focus was to eliminate any chance of future corrosion while also providing a good primer upon which our future spray-foam will adhere. Product of choice was PPG Amerlock 400, a 2-part epoxy as recommended by a super-helpful PPG industrial rep. It was applied by brush & roller @ ~4 mils DFT. We've been working in the bus for a while now since it cured, including doing plenty to the roof (painted) surface, and we're very pleased with the performance. Prep was extensive, which is the big reason it all worked out so well.

[TheHubbardBus]

Next we started cutting holes. Lots of holes. We would have cut the holes prior to painting the interior, but there was a large time gap between the 2 (aka summer), & we wanted to get the interior done before the weather got too hot to paint.

• Gravity water fill
• City water fill
• A/C inlet & passenger-side outlet
• Composting toilet vent
• Grey tank vent
• A/C (14" RV opening)
• Maxx Fan (14" RV opening)
• Multiple NMO mounts for antennas
• Cable glands for other antennas, future roof-rack items, rear view camera, solar panels
• Water & propane outlets
• Back-door washdown / shower station
• Air horn
• Other stuff I certainly forgot

[TheHubbardBus]

We were also filling a couple. We replaced our front roof emergency hatch with an 18g cold-rolled patch (SS 3/16" rivets + 3M 550FC adhesive sealant), then cut a 14" hole in it as the future home of the Maxx Fan. We also patched over the factory passive roof vent, holes cut for ill-placed antenna mounts, and more holes in the roof where the rear A/C was mounted with ~20g steel cut from the interior sheet we removed.


After all the necessary holes were dealt with, we created the internal frame / support structure for the Maxx Fan & A/C. For the maxx fan we simply re-used the support braces that formerly framed the e-hatch we deleted. For the AC we used a combination of Superstrut, 2x3 pine, and 550FC adhesive. Maybe overkill, but we could transport elephants instead of a rooftop AC now & be fine

[TheHubbardBus]

We already knew paint prep sucked from doing the floor.
We already knew paint prep sucked from doing the interior.
But the exterior... that was a whole new level of suck!


But - we sucked it up, we did the job right, and after literal weeks (yes, weeks) of back-breaking labor, we finally were ready to paint. Or eat off the bus. Or both.

[TheHubbardBus]

I was so busy prepping I didn't have it in me to take pics at the same time. But we did so much. To include:

1) Every trace of silicone used by prior peeps was removed. Paint hates silicone. I hate silicone. I hate those who used silicone on our bus. But most of all, I hate removing it. The best way we found was to remove as much as possible mechanically, then use xylene and/or contractor-grade adhesive remover to soften it enough to mechanically remove the rest. Any painted surfaces that had silicone on them we sanded down to bare metal after removal, just to be sure it didn't destroy paint adhesion.

2) Every single seam was inspected, cleaned, sanded, grooved (to apply new sealant), and then resealed using 3M 550 FC adhesive / sealant. Every single rivet or screw was inspected, and where necessary, replaced. Thankfully, the sealant used when constructing the cap is compatible with the aforementioned polyurethane sealant I used, so in places where the factory seals were intact (>90%), we simply cleaned & abraded the old sealant, & applied the 3M over the top, & it adhered great. I then went inside and hit every seam again, just as backup if any got through the already-bulletproof exterior. Mr Beefy is officially leak-free, I guar-an-tee.

3) Bondo & sanding primer were used to fill in all the necessary dings, divets, and scratches which couldn't be sanded out. There are a couple dents that would have been nearly impossible to pull out & too big for body filler which we just left. But for the most part we created a clean, flat surface.

4) Multiple power-washings, degreasing with simple green & TSP, etc.

5) Sanding went from 180, to 220, to 320 dry. An orbital was an absolute necessity, but we ended up going over the whole thing by hand w/ 400 grit as the last step, mainly because I had to use it to sand so many curvy areas (hood, front end, etc) that finishing off the flat stuff by hand was no big deal. I originally planned on taking the whole thing down to bare metal, but after testing the adhesion of the factory paint (excellent adhesion), and testing to assure the primer wouldn't lift it, it made more sense not to. Still ended up going to bare metal on roughly 10-20% of the exterior as required.

6) All rubber / trim / lights / etc removed. Front fenders removed. Front door removed. electric panel & battery box doors removed. Windows were already removed. All weatherstrip removed.

[TheHubbardBus]

Prep was sooooooooooo labor-intensive that once we got to paint, it felt like a cake walk, even though that cake-walk lasted the better part of a week.

Here we are getting ready for the big day(s). We chose Axalta Corlar 2.1 ST for the primer, and Axalta Imron 3.5HG for the paint; both industrial 2-part (catalyzed) coatings. The former is a high-build mastic epoxy, and the latter a high-gloss polyurethane. We chose these coatings based on many factors. We wanted the ultimate in durability, but due to economic, environmental, & safety concerns, weren't able to spray. The aforementioned products are not only tougher than a box of rocks once cured, but also are designed to be applied by brush & roller.

Even without spraying, these coatings - which are isocyanate laden - are quite toxic. 1/2 face respirators w/ organic vapor cartridges are a must. We changed out for new filters at then end of every day (perhaps overkill, perhaps not, but I'm hoping to spend more time in the bus when finished than doctors offices).

[TheHubbardBus]

First primer, then paint. The first 3 days were spent priming, the next 3 paint. The paint goes right over the epoxy primer without prep if you stay w/in the recoat window. We never planned on sanding between primer & paint, or between coats of either. Which is good, because the primer, specifically, is not made for it.

[EastCoastCB]

I'm loving this, and you're doing great!

[TheHubbardBus]

Imron in white base was pretty cheap (relatively speaking), so I'm glad the roof was destined to be blanco. But we really wanted a teal-like color for the body. So we hit up Lowes hardware, found a paint card we liked (Midnight Bayou... Gator would be proud), and mailed it over to our online paint supplier. Hazmat fees blow, but not quite as much as trying to source industrial paint locally.

Way back in this thread we posted a photochopped image of our bus as we envisioned it to turn out. The color of that picture is almost a dead-on match for what we achieved. It worked out perfect!

[ol trunt]

Great prep job! Your paint job will last the life of the bus.
Jack

[TheHubbardBus]

We barely - and I mean barely - got the last bit of paint down before it turned cold & rained, and that lasted a few days. 18-24 hours after the end of the last coat it started coming down. THANKFULLY I don't think it affected the cure (and for this reason, we're also very glad we went w/ a catalyzed paint), but time will tell. From the work I've been doing post-paint, it seems to be just fine. But we haven't torture tested it yet.

But now - we FINALLY get to start installing all the fun stuff we've been sourcing, stocking, & saving up for. Lights, inlets, outlets, horns (hehehehehe), etc.

All lights everywhere were replaced by LEDS. For the rear flashers, we wired the LED replacement reds & ambers into the STT circuits, & swapped out light positions so the turns were the furthest to the sides. The red flashers were only wired as stops, as from what I think I know, they're too high to legally be used as tail lights (they might qualify as 'markers', but I didn't want to get into legal ambiguity, & I can easily change that in the future if warranted). Up front we did the same with the amber flashers, and replaced the Reds with 7" backup lights on a separate switch (yet to be wired) to use as off-road accessory lights.

Since it would have been a bitch to fill in all the holes from the old markers (Weldon 5000) to use new LEDS, we instead replaced the bulbs alone with Philips LEDs, as well as new gaskets for the same. The bulbs work great, but the light distribution leaves something to be desired. Where the incandescent bulbs made the whole light 'shine', the LEDs highlight the bulb, which since it's mounted off-center in the housing, also makes the light source off-center. I don't mind much - but it might bum some people out even more anal retentive than myself.

[EastCoastCB]

Looks great man!

[TheHubbardBus]

Poor shot of the roof, standing on our house roof, this is the best shot I can get. Here you can see our roof patches, cable glands (2" lengths of scrap coax used to temporarily seal), newly-installed Maxx fan, and clear hatch. We really wanted to retain the emergency-hatch functionality, but have something we could see through too, so we bit the bullet & bought a clear hatch assembly. A happy coincidence - the tint matches the Maxx Fan almost exactly. It was ordered for the chassis, so the curvature of the roof was already accounted for. Except for swimming in sealant (is it possible to apply this crap without it getting everywhere?), it was a fairly easy job. Sealant used was Sikaflex 201 (a moisture-cured polyurethane like the 550, but much less 'permanent' in nature), which will also likely be used for the side windows.

The 2 black bits are caps on nmo mounts waiting for antennas, as well as a direct mount Sirius XM puck antenna. The clamps in the A/C opening are there just because the sealant's still curing. On either end there are items you can't see... grey tank vent cap to the rear, another cable gland up front.

[EastCoastCB]

I've been shopping around looking at single stage industrial and automotive/fleet coatings. Just can't make up my mind what direction I wana go with that.

[TheHubbardBus]

@EastCoastCB,
@ol trunt,

Thanks so much! Sorry for the rapid-fire posts, but I'm trying to catch up & maybe still have time to get some work in today! Really appreciate the comments.

Up close the paint job would make citrus fruit blush, but that was expected, and for the most part it's consistent. From a few feet away it looks great. With my eyes you don't even need those few feet