Waterproofing plywood for trailer floor/deck use

[JOEPRO]

I am a poor government worker


Plus - what the hell do I do with the plywood I already have? It will just end up annoying me and getting in the way.
Not to mention the bitumen paint, I have no other use for that either!

At this stage, I am committed to my (probably flawed) plan!

Did you price the buffalo board and how much was it compared to your ply and paint system?

If you factor in your time to paint all that I think there can't have been much in it unless the Buffalo stuff is 3x fortunes I'm not sure.

When I ordered my trailer a few years back I paid extra for a galv steel checkerplate floor. So it doesn't damage and will last for my lifetime I think.

Most UK ply is now brought in from China! And cracks apart like a fortune cookie when exposed to any rain.

 

[Smouser]

Did you price the buffalo board and how much was it compared to your ply and paint system?

If you factor in your time to paint all that I think there can't have been much in it unless the Buffalo stuff is 3x fortunes I'm not sure.

When I ordered my trailer a few years back I paid extra for a galv steel checkerplate floor. So it doesn't damage and will last for my lifetime I think.

Most UK ply is now brought in from China! And cracks apart like a fortune cookie when exposed to any rain.

Ultimately, buffalo board would have been the fastest, easiest and the longer lasting option.

I would have needed 4 boards and the cheapest I could find would have been £400 - £500 delivered.
Some buffalo boards/phenolic plywood boards costs up to £300 EACH

The three main reasons I am messing around with 'normal ply' are:

1. I already spent a lot of ££ on other new parts for the trailer (new wheels and tyres, all new lights and electric cables, new brake cables, new brake rod, new suspension bushes, new bump stops, galvanizing paint etc) and costs were really starting to get a bit ridiculous.
2. I got the 'normal' plywood for free
3. Treating the plywood with 5 star wood treatment and bitumen paint = £100 without accounting for my time.

If I didn't have to replace so many other parts I would have been happy to pay the £ for phenolic plywood/buffalo board.

 

[RonMig]

Don't forget to treat the boards underneath, too...

 

[Smouser]

Don't forget to treat the boards underneath, too...

Arguably more important than the top!

The top will at least get some protection with the aluminium treadplate.

 

[Smouser]

Update on the trailer.

Last week I got my torque wrench out to torque all the new U-bolts.
Ifor Williams recommends that the U bolts be torqued to 140Nm.

The new U-bolts and bracket plates came from a seller on eBay who has got 100% feedback and sold thousands of items.

The first red flag was that Ifor Williams recommends flanged nuts (only found that out later) for their U bolts but the ones which arrived were just 'normal' nyloc nuts.

Armed with the torque wrench, I got torquing, but the first nut/U bolt stripped before it could reach the recommended torque. Oopsie.
At this stage, I thought I would have to order one replacement U bolt.

I decided to change tactics and torque the bolts in stages which is probably best practice anyway. The plan was to torque them all to 100Nm, 110Nm, 120Nm and finally 140Nm.
All went well up to 110Nm.
At 120Nm the bolts/nuts started to strip again. Aaaaarrrgghhh.
A quick Google search for recommended max torque for M12 bolts delivered the following:

From the table, I suspect I have been sent 8.8 grade bolts with a recommended max torque of 99.8Nm instead of the 10.9 grade bolts which should be good up to 143Nm.
Although the U bolts and brackets are after-market items, they are being advertised to be suitable for an Ifor Williams trailer with double-leaf suspension so I was not happy with the items and seller.

One of the nuts/bolts stripped so badly I could not even remove it, it just kept spinning. In the end I got the grinder out and cut it off.

I contacted the seller and explained that the bolts were not suitable as they could not be torqued to specification.
The seller did not reply with a message and only sent a return label.
So I sent them back.

I decided to buy new U bolts and brackets from a different source while I waited for the return to complete with the correct flanged nuts which look like this:

A few days later I got an email saying I had received a refund for the item. However, upon checking the seller only refunded 49.99% of the purchase price with a message saying "From damage to the base plates and bolts, we suspect the item has been overtorqued by user".
Firstly, there was no damage to the base plates.
Secondly, they are probably correct in their statement that the bolts have been 'overtorqued' but they failed to mention that they sent the wrong grade bolts (8.8 grade). 8.8 grade bolts were never going to be able to withstand 140Nm.
Opened a case with eBay and the case was found in my favour within 2 hours.

I left negative feedback for the seller stating all the facts but the next day my negative feedback was gone.
Again I conducted a quick Google search and found some similar stories online of negative feedback disappearing.
Look at this example:

Unfortunately, the next customer will now also buy substandard u bolts for their trailer. Sigh.


I am happy to report that the new replacement u bolts and brackets torqued up to 140Nm without a hitch!

While this was all going on, the Black Jack 901 bitumen paint also arrived. According to the technical specifications, it can be applied when the temperature is 5 degrees +.
With the cold weather we had in the UK I decided to do a little test to see if the paint will actually dry.

I painted the end (smaller) board with a brush on one side and also did a couple of edges as the test subjects.

The next day, they were touch dry (but still softish).

 

[Smouser]

Over the next few days, I painted the rest of the boards, with a roller this time, a paintbrush was way too slow.

The first coat:

After three coats:

I was quite happy with the result. It looks to me like the boards will be 100% waterproof.

Tonight I quickly threw them on the back of the trailer when the rain calmed down a little a bit.

The last board did not quite fit, I think the paint on the edges made it just slightly too big to fit. Something I will rectify tomorrow if the weather holds up.

 

[Turbo]

Bitumen paint never fully dries & on a hot day it will get softer.

 

[prepman]

I also bought a 'lemon' Ifor williams..... but a mini-digger version. So much wrong with it, it was unreal. I did buy the treated ply deck off them, but put an ali chequer plate on top.
The proper ply was NOT astronomically priced. Had a big issue with them about the torque settings for the axle U bolts. They quoted a ridiculous figure for them, which snapped the bolts. I even got Trading Standards involved...to no avail. It's been sat unused for years now, only just got a vehicle suitable to tow it. Modified the ramp by adding the props as the fitted corner props were lethal.

 

[Smouser]

Bitumen paint never fully dries & on a hot day it will get softer.

I hope the Black Jack 901 fully dries. On the product sheet it says "When dry, the product forms an odourless and taintfree black film suitable for metal protection as well as overcoating wood and felt."

However, even if it does not, it should not be a problem because I have got the aluminium tread plate to go on top.

I think it is one more case of wait and see.

 

[addjunkie]

Don't screw screw tread plate down, or youll let water into the boards!

 

[Smouser]

Don't screw screw tread plate down, or youll let water into the boards!

I will have to screw it down. The treadplate is thin used slightly warped aluminium plate and won't stay in place.

I could drill the holes, put the screw in and then maybe use a syringe filled with Black Jack 901 to 'squirt' a bit of paint around the screw and then screw it in.

To finish off, I could paint over the screw.

Not really sure how well that will all work but I guess it is another wait and see.

 

[8ob]

Nice work @Smouser Pretty sure you will get a tidy few years out of that decking, I think mine lasted ten years with no protection and that was more destroyed than rotten.

Bob

 

[prepman]

From the table, I suspect I have been sent 8.8 grade bolts with a recommended max torque of 99.8Nm instead of the 10.9 grade bolts which should be good up to 143Nm.
Although the U bolts and brackets are after-market items, they are being advertised to be suitable for an Ifor Williams trailer with double-leaf suspension so I was not happy with the items and seller.

The 'U' bolts supplied to me were direct from Ifor Williams and the same story as yours. Still not resolved as they're 8.8.
The 'lady' in customer help department was adamant that they could be torqued up by them, I wanted to witness this miraculous event, but was told due to health and safety I wouldn't be able to..The previous conversation with the maintence team was that they tightened by 'feel' (later denied)
Trading Standards told me that everything was in order (Order of the Masons?) and could not reveal the method as it was company confidential/secret.
Where did you obtain the correct ones? Wonder if a class action could be brought aginst Ifor Williams? I was so incensed by this I contacted a test lab in Trafford Park, but didn't follow it through.

 

[Smouser]

The 'U' bolts supplied to me were direct from Ifor Williams and the same story as yours. Still not resolved as they're 8.8.
The 'lady' in customer help department was adamant that they could be torqued up by them, I wanted to witness this miraculous event, but was told due to health and safety I wouldn't be able to..The previous conversation with the maintence team was that they tightened by 'feel' (later denied)
Trading Standards told me that everything was in order (Order of the Masons?) and could not reveal the method as it was company confidential/secret.
Where did you obtain the correct ones? Wonder if a class action could be brought aginst Ifor Williams? I was so incensed by this I contacted a test lab in Trafford Park, but didn't follow it through.

What a disaster! I would have been SUPER annoyed if I bought directly from Ifor Williams and they provided the incorrect specification bolts. With aftermarket stuff, you know you take a little bit of risk at least.

The second lot I bought was also from eBay and it says 'High Tensile bolts'.
No mention if it is 8.8 or 10.9 grade bolts but at least they torqued up to 140Nm and they came with the flanged nuts.

I also suspect that many people who bought U bolts from the original supplier I have bought from just do them up by feel and don't use a torque wrench. Hence the zero negative feedback on that item. Then again, as I have said, the negative feedback I left just disappeared

 

[prepman]

What a disaster! I would have been SUPER annoyed if I bought directly from Ifor Williams and they provided the incorrect specification bolts. With aftermarket stuff, you know you take a little bit of risk at least.

The second lot I bought was also from eBay and it says 'High Tensile bolts'.
No mention if it is 8.8 or 10.9 grade bolts but at least they torqued up to 140Nm and they came with the flanged nuts.

I also suspect that many people who bought U bolts from the original supplier I have bought from just do them up by feel and don't use a torque wrench. Hence the zero negative feedback on that item. Then again, as I have said, the negative feedback I left just disappeared

One worrying thing is that if the bolts are torqued too close to their elastic limit, any additional strain could make them fail. I can't quite understand what exactly Ifor Williams are up to?

 

[armalites]

It's very easy to get sucked into cheap trailers and end up spending more money than buying a decent one, the only saving grace is new Ifors are big money now so as long as you look after it you'll be ok. Your chassis looks to be in good order.

I recently did the suspension bushes on mine, I took the leaves apart and sand blasted them too. I replaced the u bolts and I remember thinking they felt a bit tight. I have a feeling I torqued them to lower spec. I need some boards but as you found phenolic coated ply is £100 a sheet minimum now, if you want to do it properly you need to hire a tool for the Huck Floortight fixings. The tool costs £2K

The most important rule/mantra "Trailers,chainsaws,wives and girlfriends, never let anyone borrow because they always get ....."

 

[Migmac]

Our old trailers had hard wood boards as a floor, ali tread plate was put down where our quads would run. It wore out as quickly as wood did. It was cheaper and easier to replace the boards as needed. My new trailer had buffalo board in it, so far it’s doing well. Slight wear where my quad sits

 

[Smouser]

The most important rule/mantra "Trailers,chainsaws,wives and girlfriends, never let anyone borrow because they always get ....."

Hahaha. I will heed your advice with the wives, girlfriends and chainsaws.

However, I borrowed trailers on 6 occasions from friends. I will need to repay that as a minimum to ensure world balance remains.

 

[Smouser]

Deck is on and screwed down.

Next up is the aluminium plate. I need to get some 16mm screws and some black silicone sealant before I can do the aluminium plate though.

Maybe tonight.

 

[roofman]

Over the next few days, I painted the rest of the boards, with a roller this time, a paintbrush was way too slow.

The first coat:
View attachment 428249

View attachment 428250

After three coats:
View attachment 428251

View attachment 428252

I was quite happy with the result. It looks to me like the boards will be 100% waterproof.

Tonight I quickly threw them on the back of the trailer when the rain calmed down a little a bit.

View attachment 428255
View attachment 428253

View attachment 428254

The last board did not quite fit, I think the paint on the edges made it just slightly too big to fit. Something I will rectify tomorrow if the weather holds up.

I am sorry to disappoint you my friend but that plywood will absorb water through that primer over a short time...its not a waterproofer on timbers only a primer for other bituminous products despite what it says on the tin.