Friday, June 15, 2018

Trailer rebuild Ep7 - frame welds, wheel assembly

Used a 1/2 ton chain block slung off a stout rope to lift/ flip the frame over easily.

Frame separation _the old and new



Cutting up the old frame

Welding joins up with 2.5 mm rods

Welding all joins down hand - flip frame over to do other sides

Fillet welds

The running gear needed a clean up, one wheel was seized. So dismantled everything there.

Hub and spring assembly inverted for disassembly, axle u-bolts at top

The wheel seizure was caused by rusted (and expanded) brake pad backing plates. Unbolted the U bolts holding the wheel assembly's on, unbolted the leaf springs. Bolt threads etc were a bit corroded so it took awhile with penetrating oil and elbow grease.


Dismantled for maintenance_axle and hubs


Unbolted the brake calipers and removed the brake pads. These needed rust treatment, chipping layers of rust away, one pad was de-laminated from its steel backing plate so epoxy glued it together. Cleaned axle grease out of the inner hub with old newspaper (it squeezed past the inner seals due to bearing buddy grease pressurization) The bearings seemed OK as they always were well greased by the bearing buddies. The hub housing and brake discs are a very robust looking design, (the brake discs are about twice as thick and smaller diameter than the ute's front disks_which, by the way, were recently honed and re-padded by a local mobile wheel specialist)

Temporarily reassembled the brake callipers and pads so as not to loose any critical components (being a vintage era trailer they could be hard to find)


Wheel hub bearing housing and disc brakes


Started rust treatment on the parts. Chipping and phosphoric acid. The axle wasn't too bad_ its made of 40 mm solid rod bars, very heavy construction.

 The box beam (for the leaf spring attachment) on the mudguard needed more work. These fittings have probably never been separated from the trailer frame for decades, so crevice corrosion occurred between them. The trailer was coated in a high build epoxy paint though which kept allot of corrosion at bay but once rust get underneath the paint it is lifted off.

The mudguard box bar_hollow and sealed at ends so no internal rust. Good for a restoration on the exterior surfaces.

Trailer frame finishing work. Trimmed the end beams off, welded on brake wire eyes (made from heavy chain link) and ground-off welded joins and sharp edges etc.

Possible keel slide beams with an aft roller

Started thinking about the keel roller refit. There is nearly a ton of boat plus gear weight concentrated over the aft three frames, at least one roller pin had bent which prevented turning under load which was probably one of the the hidden causes of the boat getting stuck on the trailer when launching.

Found that 4x2" hardwood beams fit nicely on the aft frames, leaving a 15 mm gap between (for a water hose jet to clean the centerboard case). These can bolt on to the beams channel flange and would be capped with teflon-like plastic for easy keel sliding. Rollers can then be fitted fore and aft the keel slide woods. The only downside would be crevice corrosion between wood and galvanized steel beams_ maybe some mastic could keep the salt water out between maintenance checks.




Trailer frame rebuild Ep6 and draw bar

A bit more very part-time progress on the trailer build and refit.

The new draw-bar was extended considerably, the idea being that when on a boat ramp launching the tow car rear end can stay well clear of the waters edge and the boats keel should be a bit deeper and easier to float off and on.


The forward frame which holds the tilt hinge for the draw bar was moved back a bit from the original ones location. It just seemed like a stronger arrangement and i'm hoping that tilting the boat will also become easier. The new forward frame made from heavy steel channel was therefore longer than the original one.

Fitting the T-end

Fitting new forward frame to T-end


Aligning the draw bar , tilt hinge and trailer frame took some eyeballing and a center string line.

Tow hitch fitting

The tow hitch refitting. Used the old attachment plates and bolts. Aligned and tacked them on, cut a slot for the brake lever arm to go through the beam. After fully welding all joins, 12 mm holes were drilled to allow for air escape from potential air-pocket corners (when in the molten vat)


Draw bar under towhitch area.

Draw bar attachments for tow hitch, brake lever slot.

Tow hitch adaptor plate - lugs are for brake lever pivot. Tilt hinge pin below.

Trailer and draw bar taking shape

At this stage the frame was welded up on top with down hand welding using 2.5 mm weld sticks on the 3-6mm thick steel joins.