I am currently working on finishing up making the bents for a partly straight and curved Trestle for the return loop on my Garden railway. The Trestle is about 10 feet long and 39" tall. I was wondering what other people are using to protect thier trestles from the elements. I am in the Houston area, so we get lots of hot sunny weather as well and high humidity as well as heavy downpours in the summer and fall. I am using Ceder seasoned and cut from Ceder 4x4 posts for all the parts of the bents. On the prototype bent I made I used Spar Varnish to seal and protect it, but I am not that happy with the way it looks now that it is dry. It is a bit too shinny. Any suggestions on what I should use to seal and protect the ceder? I was thinking Tompson water seal as an alternative to the Spar varnish.

Dan Stuettgen

Used motor oil? I know others have used it and supposedly it gives a creosote look. I would think Thompson’s would work and it is dull. Of course if you keep it from sitting in standing water untreated cedar should last a long time on its own and weather to a nice grey.

boiled linseed oil, dip bents in a stain to color you want then overnight in linseed oil, motor oil, Thompsons, any of them should last quite a while. Deck stain either clear or tinted, would work too. or allow them to weather on their own.

Edit to say see the post about 3 down , A New Adventure, more answers to your question

PS Pictures of the trestle would be nice too! Just for our viewing pleasure

I dipped the lower end of my bents in Thompson’s water seal. Now, several years later, the bottom of each and every pile of my bents has rotted off somewhat. The trestle is still solid, but I had to put flat stone under each pile so it was actually sitting on something. My planned repair is to trim off the ends of my piles, and replace the lower parts with PVC lumber.

I had my piles standing on a concrete slab, the slab and bottom of the bents where covered in a layer of broken shale. The shale gave a nice finished look, but held water enough to eventually rot the ends of the piles.

In my experience Thompson’s needs to be reapplied every year or so or it just doesn’t protect well. Something I found easy to forget until it was too late.

My experience is with used oil; father-in-law was chief mechanic in a silk mill years ago–when changing equipment and flooring in the building, gave me some old heavily soaked 2.4’s that I used as ground framing under lattice at front porch. These were heavy and rock solid but in the end have rotted out.

Hi

My experience is that cedar will weather well turning gray and last for years in Maryland. You can apply wood preservatives, but as above, they only last a year if that. Want a creosote look, use fence paint a black asphalt paint for farm fences.

However, any wood in ground contact will rot, so your job is to delay that on the bottom of your bents as long as possible. First approach is no ground contact at all, pour concrete footings or put bents on bricks, etc. However that may or may not work for your situation, in any case:

I suggest using an oil based paint on the bottom of the bents and as far up as needed to get above ground moisture

Some candidates are an oil based house paint primer. They are white, but can be tinted any color you like

And I have used Rustoleum “rusty metal primer” which is a dark brown color and it works for quite a while, soaking the pieces in a can for a while.

PS- Spar varnish is lovely, but hopeless as it will yellow and peel after a year or so and be impossible to touch up on a trestle…

Let us know how it goes

Regards

Jerry

I’m a big fan of motor oil for any wood going into the garden.

Best,

TJ

I went with a mixture of Minwax Ebony stain and Boiled Linseeed oil for my latest Cedar bridge deck. Here are my stain color experiments…

Here are some tests with the addition of Boiled Linseed Oil. I forget which formula I ended up using, but I can look it up if interested…

And here is the resulting deck after adding the Boiled Linseed Oil…

It’s only been outdoors a few months, but so far it still looks great.

Thanks for all the input guys. It seems there are as many ways of protecting the trestle bents for rotting as there are ways to build them. I have pretty much decided to just stain them with a nice light oak stain and then coat them with a clean polyeurathane and be done with it. I don’t stain or seal my ties and I like how the weather and turn grey and the spikes rust leaving black stains on them. The trestle bents will be resting on top of 1" thick slabs of Limestore that are sitting on a base of Crushed granite. I hope to have the trestle built either this weekend of next weekend. I will post pics as it goes in and when completed. Dan

I just use a thick layer of stone underneath. This keeps the bents from being directly in the ground were the moister stays longest. It helps the water drain away and dries up fast. Also applying linseed oil or motor oil will help as well.

Getting wet doesn’t really do the damage to wood. It is not being able to dry between wettings that causes the issues with molds and dry rots.

As long as the wood can dry it will hold up for a long long time.

Coatings like polyurethanes, varnishes, and some water repellents create a barrier between the wood and the outside environment. This seems like a good idea, on the surface so to speak, but it really isn’t. Water will get into the wood some place some how no matter how careful you are and that barrier that keeps water out will keep it in and problems will follow.

My standby is used motor oil thinned with diesel fuel it soaks into the wood and slows/prevents moisture penetration. If moisture does get in it can get back out during a drying cycle. I have wood bridges that have been out for over 10 years that are treated with this every couple of years and they are as solid as the day they were built.

Wood buried in dirt will rot no matter what it is treated with, that is why the 1:1 railroads bury ties in rock ballast, so it can dry between wettings not because they like spending money on rocks.

Just my opinion.

Rick

Rick Marty said:…that is why the 1:1 railroads bury ties in rock ballast, so it can dry between wettings not because they like spending money on rocks.

And here I thought they did it because it looks so cool! (http://largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-cool.gif)

Double post. Sorry.

"In my experience Thompson’s needs to be reapplied every year or so or it just doesn’t protect well. Something I found easy to forget until it was too late." Gary Buchanan

I will affirm that statement. Thompson’s is NOT durable. The most effective sealer I have used – 12 years of service – for trestle bents is to literally paint them with a non-transparent (essential for durability) stain. I use Behr brand exterior stain.

Check Consumer Reports back issue on stain research for coverage and durability. Behr, non-transparent, got the nod for both durability and appearance.

My bents sit on some gravel. Some are 25 years old, all gray but still fine. They are redwood. So the wood can make a difference. Hard to stain them , once they are up with track on them.

Yea, mine are cedar, and even with Thompson’s they only lasted about 6 or 7 years before the bottoms had rotted off. Redwood is very pricy round here, so that’s why I went with cedar.

Redwood is fairly inexpensive here. A 2X4X8 is much more than 4 or 5 dollars. If anyone wants some and want to pay for cost plus shipping I will send you some. Not sure its worth it but the offer is open.

David Maynard said:
Yea, mine are cedar, and even with Thompson’s they only lasted about 6 or 7 years before the bottoms had rotted off. Redwood is very pricy round here, so that’s why I went with cedar.

Thompson’s requires reapplication each year, and is not rated for constant contact with the ground. Even Cedar and Redwood with deteriorate in those conditions. A concrete or plastic pier is required, to provide good drainage. Soaking in some kind of oil to penetrate the wood is of great benefit, too.

Steve, I plan on rebuilding the lower story of the trestle with plastic wood, maybe next year.