Dimensions of trailer cross bars…

I'm gonna go out a limb here and say... if the boat is 8.5' wide, than the trailer needs to be that wide so you can attach strap hooks and so forth next to the hull cradles.

If I had to "--engineer it" then thats what I'd bet on.

Let me try to restate my question, and make my request less ambiguous…

What I am really wanting to know is the box cross section dimensions…is it 1-1/2” X 1-1/2” ??? or 2” X 2”??? square…and what is the wall thickness…If I have that, I can call up the machine shop and ask…( lets say for example it is 2” square with a wall thickness of .125”)… what will two pieces of galvanized square stock 2” X 2” with a wall thickness of .125”, 8’-6” long cost me…? I need to know what the box dimensions are? And what the wall thickness is?

Thanks,
Bob

Don't use box! Use C-Channel. Box will hold water and rust out pretty quickly! My trailer is at a lot or I'd go measure it for ya, but it's nothing bigger than what you'd see on a small bass-boat. These boats weigh well under 1000lbs and don't require heavy-duty trailers.

My 6.0NA trailer has 2" sqaure tubing with a 1/8" wall. The unsupported ends extend 24" from the trailer box frame and are almost 8.5" long.

Jake

Thanks Jake...that's exactly what I was looking for...

Bob

sure - note that I meant overall length is nearly 8.5' (not 8.5"). It's probably closer to 8'

Just in case anyone else is interested in doing this, our local machine shop wants $63.00 for a 24' stick of 2" X 2" 1/8" walled galvanized square tubing...said it was cheeper to buy the whole stick than have them cut two 8'-6" pieces..

Bob

Remember that once you cut it the area where you cut it won't be galvinized. You could just spray a little silver rustolium on the ends to keep them from rusting. Anyplace you cut or drill is a place where rust can start.

Mike Hill
H20 #907

Yep...thats what they make cold galvinize for...

I'm curious, because this is almost twice the amount that the local industrial supply warehouse here wants for an identical piece of non-galvanized.

If the price difference is because of the galvanization, then you might want to take the approach I am with my new tilt and just put the whole thing together then give your buddies a case of beer to help you coat the whole damn thing in POR15.

Better than galvanizing IMHO. AND you can get a bright yellow trailer at the same time!

what's POR15 (poor 15?)

Don't forget that when you cut the galvanized tube, the cut ends are not coated.

Not exactly sure what it is chemically, all I know is that its bulletproof. The antique car guys use it to coat car chassis parts.

basically, my car buddy says that its the stuff that all the hot rod and street rod guys are using to preserve all their junk. Its not a paint per se, more of a coating. He says that if its going to be exposed to sunlight for long periods of time, then you really should paint on their supplied primer and then put a topcoat of something on it to protect it. He says overall, that he trusts this stuff more than galvanization to protect from rust.

He says a simple internet search will provide answers to your questions

More like three times the price…bare steel was $23.80 for 20’, Galvanized was $63.00 for 24’. I live in Florida, I live on an a barrier Island, I do all my boating in salt water, and if its not an Aluminum I beam trailer, or Hot dipped galvanized it won’t last anytime at all…

How many times will you have to replace bare steel in comparison to Galvanized steel? How about your time spent? For an extra $40 bucks I would rather do it right the first time…. Ends touched up with cold galvanize paint.

What is that they say?…Never can afford to do it right the first time…but always can afford to do it a second time…LOL

What you friend is suggesting sounds like some sort of Epoxy if it has to be top coated when exposed to the sun (Epoxy paints generally chalk badly in the sun). Remember when you are painting (coating) steel all you have to have is one little nick in the coating and its all over…think about vinyl coated steel car racks…thick rubberized plastic coating, but the moisture and salt find there way under the coating and the whole thing turns to crap. Galvanized is much more forgiving in a trailer environment.

seeker,

I asked about the chipping specifically.

he said that they use this stuff on everything from chassis parts to axle housings to engine blocks. He said that theres never been something this tough.

But most cars are not immersed He may be right MauganH17 about it being really tough in the car environment...but most cars are not immersed in salt water...or even exposed to the salt air environment that a cat trailer is...like I said all it takes in one little nick, gouge, place where it didn't get completely coated and its going to start rusting...beside most of those car guy are really anal about keeping their babies super clean.They would never have a chance to rust anyway...

except cars where they put salt on the roads.

I don't think you're getting the correct impression. This stuff is like spray-on rhino liner but tougher. It doesn't chip, period.

For anyone builing a trailer, you can have it hot dip galvenized after it's built. Most large cities have a facility, look in the yellow pages. You will have to take it apart and pull off anything you don't want dipped in acid or molton zinc. The yard will charge you by the weight of zinc they put on. My tilt trailer was done that way and shows no rust after 10 years.

I asked my materials people about POR15 for extreme salt environments vs galvenizing. The response was, for long term (10+ years) it is something you might want to put over galvenizing but not instead of galvenizing.

It was interesting, painted galvenizing (the process used for good car fenders) is rated for 1000's of hours exposure to salt spray vs 10's to 100's of hours for most coatings.

Carl, what did it cost to galvanize the tilt trailer in question?

On the issue of trailer STRENGTH.
It is true that very few of us carry more than 1000lbs of weight, but gross capacity is not our biggest problem.
Trailer FLEX is.
Because of the length and center of gravity of our boats, our trailers are very long.
This length causes a great deal of both vertical and lateral flexing while traveling.
The welds and the area around them are especially susceptable to damage from flexing.
I have repaired several of my trailers and helped fix others.
We need STIFF trailers.
If I were building a trailer from scratch, I would make the frame as large and long as possible and add reinforcing plates at the welds.
And have it dip galvanized.

I can't answer that question because I didn't build it, it was built by Texas Tilt (Doug Graf). Doug told me how he did it but, not the cost.

I have helped with smaller trailers (10 years ago) and was told the bids $150 to $600

I have had smaller items galvenized and there was a big difference in the bids (a mast support was $10 to $105) so it pays to shop around.

The best work was done by a big company who "tucked" my job in with a big job for a railroad. The worst job was by a small shop

Some trailer builders that hot dip their own trailers will offer this. I was told a rough rule of thumb was 1.5-2 times the difference in price between a painted and galvenized similiar trailer.

Now you know as much as I do

Comercial galvanizers I know have a $200.00 minimum. The price went up a lot in the last three years. (The EPA charges you for the right to polute). The price is generally figured by the pound. Almost as much as the original steel, so say 25 cents per pound, and a surcharge if it is tubing...so a 300 pound trailer of channel section is $75.00.
The good thing about zinc is that where there is none, the rest gives it an anodic protection?
On trailer design: I'd say that a trailer needs to be as small as possible. It is too long to be "stiff", because even without the boat, it flexes. Clearly the payload is not the issue with flexture. A drawbar that attached to the front crossbar (where the weight acts)with a minimal support to the back crossbar and mast cradle, with a rubax type independent axle would be the way I'd go. Some sort of rotating arms to secure/ lower the boat to the ground, and then drive the trailer out, would be my route.

Carl,

There are a group of Southern CA Tornado owners working out plans to get 3 or 4 Tornado tilt trailers built in the next month or two. We have a few concepts that look promising. One involves an all aluminum trailer for good corrosion resistance and a "crane" post that will hoist the boat up via the main beam/hull intersection point, up into an upsidedown beam cradle fixed the the top of the crane post. The high side will then hang from this cradle only...no other support posts will be needed since the main beam is so close to the balance point of the whole boat. The lower hull will be strapped into pivoting hull cradles and thus provide all the other hold down stability needed. This has advantage of keeping weight aloft to an absolute minimum. If more weight is wanted down low for stability, a good sized storage box could be added etc.

Can you provide us any details on your trailer? Pics? Drawings? Doug Graf's contact?

Mike.

Greg Scace from CRAC maybe able to help you - I believe he has a pretty good design he came up with. Grabs the boat by the crossbeams, it gets winched up to rest upside-down supported by the beams, not the hulls.

I'm familar with the Scace design...unfortunately we all want a trailer we can also use to launch the boat off of directly. The upside down tilt type does'nt meet this requirement.

I like the scace design, unfortunately, there are other trailer designs that are far simpler to build, and less expensive that meet the above criteria.

Mike

It would hard to make a picture of the trailer right now, everything is covered for the winter. I will see what I have in the library. Design wise the trailer is standard. A reinforced "A" frame with a tongue. The tilt platform is an H with telescoping arms (so you can trailer the boat flat) with steel cradles for the hulls.The real difference is in construction. It was built like a commercial trailer. For a cat trailer it is a monster. It uses 2x6 for the lower frame, 2 1/4x2 1/4 & 2x2 for the upper and what looks like 3 in drill casing for an axel. Empty and bare it probably weighs around 1000 lbs

Your design uses the boat as the tilt platform. Steel trailers, hinges, etc damp road vibration and raise the resonance frequency. You are going to have to worry about resonance frequencies. If I don't tie my upper hull tight, it vibrates in the 0-10 hertz range.

I do not recommend launching a Tornado off a tilt trailer. It is hard enough keeping the corrosion off the expensive bits without dunking them in saltwater.

The US Tornado Assoc used to have plans for a good tilt trailer. Contact the US Sec to check.

The plans were detailed. They told you how long to cut what and how to weld, etc. Basically you could go to a self service steel yard and cut the parts. Then take them to a welding shop. Finally to galvanizer and then put it together.

When I first started, I wanted something like you are talking about. I was looking at a welded Aluminum or an aluminum upper with a steel lower. When I talked to trailer building professionals they talked about cracking problems with welded aluminum, transmission of vibration, galvanic corrosion at the hinge, and how the aero loads are dominant for the upper section. When I talked to an owner, he talked about sway, vibration and loosening hulls.

After living with the trailer for a while, I have decided that Isolating your boat from loads, stability in cross winds, ease of operation, reliability, and protecting that expensive hydraulic system is more important.

If I were going to build a trailer, I would look at the upside down system. A friend built one years ago. He claimed he might not be the fastest Tornado on the water but, he would be the fastest back on the trailer and he was.

I have the same reservations that you do about this design. I'm not sure I like the boat being the tilting frame itself. Not sure I like the raised hull just up there unsupported. I'm definitely going to build mine out of steel.

Regarding using the boat structure itself as the tilting frame, it was mentioned on the tornado group that because you have a rack itself does not isolate it from flexing. However, I think that a steel rack with diagonal tensioning rods would flex less than a free standing unsupported flying hull. They say the loads on it would be much less than a boat crashing through a wave, but I'm still a bit skeptic.