View Full Version : Raising trailer height and best paint brush anit rust coating

10-10-2011, 08:05 PM
Just purchased a 14 footer that sits on a run of the mill 14-15 foot fairly light trailer.

The springs etc attach to a forward/back moveable caddy so are not welded to the frame proper.

Does anyone have a simplified way I can raise the height of the trailer similar to the height an illegal spring over obtains or even a little bit more?

I was thinking of running another piece of frame like section under the existing frame, U bolting that to the frame then U bolting with longer U bolts than standard the caddy to both the new and the old.

In theory if I use heavier section and heavier U bolts than standard would the result be engineered safe enough? Looking for any on the road strength drawbacks that I may not have considered...or a simple but better idea.

I also need to give the trailer a once over to remove surface rust and was wondering what today is the best permanent salt water protection to paint brush coat the entire trailer with afterwards that's easy to source outside the southeast and will be better long term and just as cost effective as cold gal.

All replies welcome.

10-10-2011, 09:02 PM
Would changing wheel diameters be an option? Much less screwing around.
Placing the axle under the spring will give a few inches straight up without any mods needed.
Making a secondary sub frame would be the last resort, would opt to build a new elevated subframe with hangers rather than layering subframe over secondary subframe. Too many connections to be reliable.

I like Ensis fluid from Shell. The heavy version is a self healing tar like substance that will dry to touch dry in a week or so, any stone chips will heal over on the next warm day plus it penetrates the steel over time. I sprayed parts of my old G60 whilst they leant against a 1.6mm sheet of zinc anneal steel sheet, 12 months later there was a film on the other side of the sheet to where I sprayed the parts. Pretty good stuff but looks like shit.

Where does it state spring over is illegal in trailer designs?

10-10-2011, 09:22 PM
Ok thanks Jack I will look into that fluid, i dont care what the trailer looks like just so long as I need not deal with it again for a good while.

That fluid will last for years?

The trailer has 14inch alum mag wheels already, I am looking to tow it over bush tracks nothing too hard but a little extra clearance will be welcome at times. I think spring overs are illegal, not totally sure on this though.

10-10-2011, 09:40 PM
depending on how its setup, you could swing the axle under the leaf spring and add a one inch block between the spring and axle. i on the other hand will just get bigger wheels and lift the gaurds :)

10-10-2011, 11:06 PM
I think spring overs are illegal, not totally sure on this though.

I very much doubt it as it is a common mod done to caravans to give more clearance

11-10-2011, 06:29 AM
Hey Scott.......Are they slipper's?.........if so where the slipper part is add some rhs to the mount and re=slip the spring back in........we did it with the fatherinlaws a few years ago,ended up raising it about 40mm with no side effects.
As for the rust......mate Lano.......keep it up to it and you can't go wrong.


11-10-2011, 07:04 AM
FNQ dude...mate. You can get stepped axles which are usually used to lower a trailers height.
Just use them in the opposite direction as depicted below.
They can be in the form of basically welding stub axles on the top of an axle beam (over lay) or with a 'packer' between the stub and axle beam or a thick plate welded in like they use in the rubberised independent axles.

Personally I would not be doing any of the adding another RHS and using u-bolts to hold it all together. Just too many things, or places, for things to let go or slip.

As for brush on rust preventative....grease mixed with some old diesel sump oil and left in the sun to warm up.
Brush it on once a year and drive on the dustiest road you can find while it's all hot.
Never have a problem with rust or thieves. They hate getting their hands dirty and your trailer will look like crap but under the dirt will be as good as the day it was built.

11-10-2011, 07:14 AM
For rust proofing, tectyl 506. I think tectyl have some harder wearing versions now, but the old 506 is time tested. You need to re apply periodically though.

11-10-2011, 08:46 AM
thanks for the replies, finga that is a cracker idea of a setup, i need to remember that for the future, this trailer came with an over engineered 40 square axle and ford bearings which was originally nice to see till now :) don't think i can bring myself to replace/modify until it's time is up.

Dan no it's eye to eye but a good idea worth remembering too, i have done the fish oil thing years ago but don't consider it worthy today, sort of the same properties as lano i suspect, i am way too lazy now so i am told but i think i am simply being efficient :)

on the advice above I think i will junk the idea of adding the extra frame section, would have been a pain getting custom U bolts made anyway and will go with the old spring over setup, quick and simple with an extra leaf on the new springs I might get and keep enough height to be happy for a while.

I have used techtyl years ago with good results overall but it did flake which was probably my fault, will also look into this option again and the diesel mix might do that after the primary coating for a double up......to forget about trailer rust maintenance for 5+ years or so would be nice if I can achieve it.

thanks again, it's been more helpful than just me nutting this out.

11-10-2011, 09:42 AM
i on the other hand will just get bigger wheels and lift the gaurds :)


cheap 15in sunraysia rims and a high profile A/T tyre would raise it an inch or 3 easy ;). plenty of cheap sets on ebay (could get a pair with good tyres for under $100)
What stud pattern is it? You state 14in rims but what size tyres are on there now?
Just use the Tyre Difference Comparision calculator to work out how much different it would be - http://www.exploroz.com/Vehicle/Tyres/SizeCalc.aspx

11-10-2011, 04:38 PM
FNQ, the Ensis fluid heavy version will last for a good decade provided you don't sand and rock blast it to nothing. I hit the underfloor and inside the pan of a VW beach buggy with it once and used the thing every week end on the beach with nothing more than a light hose off on the paintwork after a run. 9 years later I sold it with zero rust in it. That beach buggy was regularly driving in the wash getting completely saturated with salt water every trip. It is good shit but looks like bat shit a while later.

11-10-2011, 04:42 PM
Be careful with Finga's suggestion if you going to invert the axle, leverages involved will quadruple the tensions on your U-Bolts if you hit a kerb or something. I would stick to a straight axle if you are going to do anything resembling offroad work. They are designed as a drop axle to lower, in that use they minimise the strain on the bolts, inverted they amplify the strain.

12-10-2011, 02:11 AM
In terms of the rust prevention...an option i went with for an older trailer (admittedly in great nic tho with no rust) was using a uv tolerant version of por15 called "sterling silver". Used for things like car chassis and engine blocks. The uv silver comes up looking like gal and its tough. There's a black top coat from KBS rust seal (same owner as por15 i think) and fine with the UV's. Benefit is u can use a brush and go straight over the rust with these things saving prep. Might work out reasonably cost effective seeing its not a huge trailer.
I then used tectyl just for axle and springs, just buy a spraycan or two every yr or so and give the axle/springs/fishplates/bolts a touchup at the ramp...seals the bits that always seem to go first like springs/boltheads/nuts/ubolts. Awful stuff in a spraycan but handy. Tis a plan like any other...never been a fan of coldgal.
You could also try the old marine penetrol, its so thin and acts as a physical barrier as it soaks into old steel/gal and fastenings. Multiple layers on frame then left as is might be an easy/cheap alternative worth trying but dont know if uv tolerant..maybe use as a primer which i believe is its general use anyway.
If u have any box x members, especially at rear, its easy to drill a few holes and pour some GOOD fishoil in then plug up. This stops the welds going which invariably rust out from the inside. Some use sump oil but u dont want Bob Brown around at the ramp. I know fishoil is old school but u talk to trailerguys and they still swear by the stuff and recommend it...as long as its not the crap stuff that floods the market. Everyone tries to reinvent the wheel and market the shit out of it to make a buck...i'm of the opinion that if something works whynot just keep using it.
Maybe ask around what the Fraser Isl 4wd guys use underneath...just throwing some other options out there.

12-10-2011, 07:02 AM
Hello All,

For the rust, I have tried marine penetrol.
I ground the rust back with a wire wheel in an angle grinder before applying two coats of penetrol, with a top coat of paint to protect the penetrol.
So I think that it had a fair go.
Absolute waste of time, rust came back in a couple of months.
Do not waste your time with penetrol.

12-10-2011, 07:28 AM
Ok thanks Jack I will look into that fluid, i dont care what the trailer looks like just so long as I need not deal with it again for a good while.

That fluid will last for years?

The trailer has 14inch alum mag wheels already, I am looking to tow it over bush tracks nothing too hard but a little extra clearance will be welcome at times. I think spring overs are illegal, not totally sure on this though.

I rebuilt my tinnie trailer last year, and didn't allow enough tyre/guard clearance. First bottom-out shorted the guard light wiring.

I moved the axle under the springs which increased the tyre/guard distance another 100mm. Now have 150mm for Lakefield trips.

When funds allow (during Barra closure) I'll modify the guard height AGAIN, and regal the wheel carriage, and move the axle back on top of the springs to make launching easier by dropping the back of the boat 180mm