Drilling into I-beam for stern tie-downs.

[JWS]

I don’t like the way my transom tie straps sit, they’re right up against the trim tabs on both sides and between the transducer and trim on one side. I’m thinking of drilling into the I-beam to move the tie down on the trailer, changing the angle. Is this a stupid idea?

I’m mostly concerned about pressure on the transducer, as i use additional softeners against the tabs to prevent chaffing over a sharp edge.

I’d like to move the trailer mount from the circle to the dot, changing the angle to more the line in red

 

[searun]

try using a tie down rope instead - better that, than drilling into the trailer I beam which will weaken it.

 

[pescador]

I had a similar problem years ago and had Roadrunner bolt on some 2x2 Galvanized steel with ”C” clamps to the main rails to essential extend out my straps past the stern. Here’s a photo. Also, my straps make slight contact with the trim tabs. I just cover the straps with a piece of carpet to reduce the risk of the straps getting damaged.

 

[Foxsea]

The outer end of this flange section, where you propose to drill a hole, has no structural purpose. (Well, it helps hold the tail lights, I suppose.) It's fine to drill a 1/2" hole, large enough to hook the straps up. Just stay clear of the ends and edges, closer to the web, so you have enough metal - say 1/2" min., remaining after drilling the hole. That's how my trailer is set up.

 

[Sharphooks]

I'm facing the same problem. Both straps go across the trim tabs....I worry way more about damaging the trim tabs when I say, go over a large bump in the road, then I do about chaffing the straps

I was just going to drill a hole in the I-beam at a better location, just big enough to get the hook of the strap through. I can't imagine that would compromise the structural integrity of the I-beam? I figure if you're going to bolt something to the I-beam, you still have to drill a hole, correct?

 

[scott craven]

My newer trailer (2019) came with holes drilled in the I-beam.
If manufacturer's do it, I can't see any problem drilling it.

 

[lemmy]

You could also buy some 1 or 2 inch webbing slings and go right around the trailer frame …. Wesco would have the bigger size for sure. Bought lots of 1” MEC climbing slings over the years . They come in various lengths and are rated for 22kN breaking strength.

 

[pescador]

Here’s a clearer shot of the mods to my trailer.

 

[Rain City]

You could also buy some 1 or 2 inch webbing slings and go right around the trailer frame …. Wesco would have the bigger size for sure. Bought lots of 1” MEC climbing slings over the years . They come in various lengths and are rated for 22kN breaking strength.

That's what I was thinking. Slings are a great way to rig things without additional drilling.

 

[lemmy]

Yup , we use them a lot , rigging in the film industry. Endless loop ratchet straps are another. Both so useful!!

 

[Foxsea]

I'm facing the same problem. Both straps go across the trim tabs....I worry way more about damaging the trim tabs when I say, go over a large bump in the road, then I do about chaffing the straps

I was just going to drill a hole in the I-beam at a better location, just big enough to get the hook of the strap through. I can't imagine that would compromise the structural integrity of the I-beam? I figure if you're going to bolt something to the I-beam, you still have to drill a hole, correct?

Inescapable logic! With 4 or 5 solutions to choose from, the simplest is usually best - quick, no cost, almost no effort (aluminum), totally reliable, nothing extra to corrode, maintain or fail. Get the drill going. 5 minutes and done!

 

[JWS]

I'm facing the same problem. Both straps go across the trim tabs....I worry way more about damaging the trim tabs when I say, go over a large bump in the road, then I do about chaffing the straps

I was just going to drill a hole in the I-beam at a better location, just big enough to get the hook of the strap through. I can't imagine that would compromise the structural integrity of the I-beam? I figure if you're going to bolt something to the I-beam, you still have to drill a hole, correct?

Inescapable logic! With 4 or 5 solutions to choose from, the simplest is usually best - quick, no cost, almost no effort (aluminum), totally reliable, nothing extra to corrode, maintain or fail. Get the drill going. 5 minutes and done!

Not sure that’s the most logical for my situation, there’s a lot going on where I’m thinking of tieing off to (lights, bolts and brackets for cross member, u-bolts for side bunks). I’m also picturing a very sizeable hole to be able to snake the strap hook into, but I’m going to have a closer look to make sure. Right now I’m leaning towards a bent piece of flat bar bolted to the webbing, staying away from the flange.

 

[JWS]

You could also buy some 1 or 2 inch webbing slings and go right around the trailer frame …. Wesco would have the bigger size for sure. Bought lots of 1” MEC climbing slings over the years . They come in various lengths and are rated for 22kN breaking

Take a 2" piece of flat bar (galvanized or other suitable metal) at the length desired to clear any obstructions and bend it at the required angle to clear the web of the I beam, drill a hole at one end to suit the strap and another at the other end to bolt to the web of the I beam at the suitable location.
Check out the rear of a Highliner trailer on line. They may even have the parts you can order at a reasonable price.

This is likely the route to go for my situation. Thanks all for your input!

 

[Alex_c]

Not sure that’s the most logical for my situation, there’s a lot going on where I’m thinking of tieing off to (lights, bolts and brackets for cross member, u-bolts for side bunks). I’m also picturing a very sizeable hole to be able to snake the strap hook into, but I’m going to have a closer look to make sure. Right now I’m leaning towards a bent piece of flat bar bolted to the webbing, staying away from the flange.

Buy some thick (1/4”+) 2x2 aluminum angle, cut to 3” long, drill a 1” hole in one side, bolt other side to trailer with stainless hardware. Boom $20 and you’ve got an eye to run the strap hook through

 

[JWS]

Inescapable logic! With 4 or 5 solutions to choose from, the simplest is usually best - quick, no cost, almost no effort (aluminum), totally reliable, nothing extra to corrode, maintain or fail. Get the drill going. 5 minutes and

Inescapable logic! With 4 or 5 solutions to choose from, the simplest is usually best - quick, no cost, almost no effort (aluminum), totally reliable, nothing extra to corrode, maintain or fail. Get the drill going. 5 minutes and done!

Not sure that’s the most logical for my situation, there’s a lot going on where I’m thinking of tieing off to (lights, bolts and brackets for cross member, u-bolts for side bunks). I’m also picturing a very sizeable hole to be able to snake the strap hook into, but I’m going to have a closer look to make sure. Right now I’m leaning towards a bent piece of flat bar bolted to the webbing, staying away from the flange.

After a second look, this may actually work for my situation

 

[searun]

You guys are waaay over thinking this problem. A simple rope around the cross member and back to the boat tie down and problem solved. That boat ain't going anywhere and there's no hole drilling involved. She ain't pretty, but a little good ol Canadian engineering simply works.

 

[Foxsea]

You guys are waaay over thinking this problem. A simple rope around the cross member and back to the boat tie down and problem solved. That boat ain't going anywhere and there's no hole drilling involved. She ain't pretty, but a little good ol Canadian engineering simply works.

You from Alberta? They always go for the rancher method - rope anything that moves.

 

[Brando]

Don’t drill a hole in a galvanized trailer it will start to rust in that location and then you will have structural concerns longer term. The mfg drill before the frames are dipped. AL different story should be no problem

 

[Squire]

Buy some thick (1/4”+) 2x2 aluminum angle, cut to 3” long, drill a 1” hole in one side, bolt other side to trailer with stainless hardware. Boom $20 and you’ve got an eye to run the strap hook through

I have the aluminum I-beam with the carriage-bolt channel but I had tabs made of bent 1/4” thick aluminum bar material to fasten to it for tie -down attachment. Prior to getting these made my straps were getting frayed on the trim tabs as well.

 

[Alex_c]

I have the aluminum I-beam with the carriage-bolt channel but I had tabs made of bent 1/4” thick aluminum bar material to fasten to it for tie -down attachment. Prior to getting these made my straps were getting frayed on the trim tabs as well.

Another option would be a small DIY beam clamp to fasten an attachment eye to the trailer.

@JWS Where are you located? I probably have the materials on hand to fab something up if you’re in the lower mainland, and you’re interested in that sort of solution