How long a sanding block do I need?

[ArAKern]

So the side of the camper has lots of shallow depression. Done my best to beat them out, but will need to put a skim of filler over the whole side.

Having never filed or sanded a bodywork before is there a rule of thumb as to how long a panel be how long the block should be to avoid waves?

 

[steveo3002]

biggest you can get for camper van sides

 

[ArAKern]

Found a 30" Dura-block is there anything else available?

 

[brightspark]

Found a 30" Dura-block is there anything else available?

no need for anything bigger

 

[steveo3002]

yeah 30 will do it

good luck getting it dead straight

 

[vw1]

Such hard work getting campervan panels straight but as said dura block. Good luck and pictures are most welcome .

 

[ArAKern]

No intention of getting is dead straight but vaguely better that it is now. Just found more welding distortion from previous repairs. I did want to replace the panel but the other half did not want to do it and was happy to fill and sand, as it's her bus she is the boss.

Wil post up some pictures

 

[gaz1]

this will get you a little wider 48"x 3 1/4"

Magnusson Darby 48 x 3¾

Order online at Screwfix.com. Adjustable and detachable soft-grip handle, for comfort whilst working. Manufactured from extruded aluminium for lightness and strength. FREE next day delivery available, free collection in 5 minutes.

www.screwfix.com

you can also fit it out with some wood and also hold down the wood to grip on the sandpaper

 

[bert]

I have a massive dura block, one of the 4.5" wide ones and it's still really hard to get them flat.

 

[Bluemotion]

Ok well I’m a madman when it comes to filling massive panels, people just stop and stare. I’ll make a massive mix and depending how deep those hollows are I’ll add resin to make it a very wet mix. It’s cheaper than ‘dolphin’ and your more in control. I’ll use possibly a six inch wide spreader or something for taped joints on plasterboard then make a medium hardener mix as adding too much will beat you. As it starts to cure I then use machine saw blades to fast cut the basic flat profile or thin hacksaw blades if I’m doing concave/convex curves. These work better in my opinion than body files as they are a deeper cut. For really bad knackered panels like roofs I’ve even used a 24tpi wood saw drawn sideways to fast cut a profile, now that’s the bit when passers by stare! This only works best whilst it’s still in the early curing stage.
Once it’s summat like then you’ll want to use some black dust guide coat. That’ll show everything up. Minimum 18” block with ‘fresh’ paper. If you start using ‘dulled’ paper your then over applying pressure you will never get a panel flat so be generous in this case.

 

[ian f]

i've seen some somewhere on youtube but can't remember who. that used a rigid block with a polycarbonate pipe attached on top to prevent flexing. i might have a go at making something similar. found a pic

 

[steveo3002]

used to use an old number as a spreader on vans lol

 

[bert]

This is my block, it's the 24" version. I will probably end up getting the bigger one at some time too

 

[Morrisman]

In the sailing boat yard in Singapore our guys used plywood boards 6' long, and 10" wide, 3 guys sat on a scaffold rubbing back and forth all day long. Sandpaper was held on with spray glue.

They added something called 'microballoons' into the filler, to make it a lot lighter and easier to sand.

 

[Keith 66]

I use microballoons for fairing boats, mixed with epoxy & a bit of cabosil to minimise sagging, troweled on with a plasterers float you can get it pretty fair before sanding. I never bothered with long boards just a black guide coat from a rattle can & rupes long bed fairing sander & air file, always run on the diagonals & never stop in one place, change diagonal direction often.
Holding the machine up for hours can be tiring so i have been known to rig up a couple of blocks in the rafters with a line run through them, the machine hangs from the middle & the ends have a brick tied on each end as a weight. Makes the machine weightless.
Another tool used in a boat factory was a square sander, basically a large 9" machine polisher with a square flexible plywood sanding pad bolted to it.
A sheet of 40 or 80 grit attached it was fast & surprisingly good at fairing big flat surfaces.
I did hear of a boatbuilder who fitted a longboard to a trackrod swivel & long rod, this was attached to the flywheel of a large slow speed motor, plugged it in & it took the hard work out of it. But as the old engineer once told me "Now we come to the sorry bit, there was no means of stopping it!"

 

[gaz1]

tech has changed enough now

if you wanted a self sander then you can use a hedge trimmers base plate and use a motor with a wire to it similare to the strimmers flex cable

this can also be made flexable enough so it follows a boats contour from the top right down to the keel

 

[Morrisman]

I use microballoons for fairing boats, mixed with epoxy & a bit of cabosil to minimise sagging, troweled on with a plasterers float you can get it pretty fair before sanding. I never bothered with long boards just a black guide coat from a rattle can & rupes long bed fairing sander & air file, always run on the diagonals & never stop in one place, change diagonal direction often.
Holding the machine up for hours can be tiring so i have been known to rig up a couple of blocks in the rafters with a line run through them, the machine hangs from the middle & the ends have a brick tied on each end as a weight. Makes the machine weightless.
Another tool used in a boat factory was a square sander, basically a large 9" machine polisher with a square flexible plywood sanding pad bolted to it.
A sheet of 40 or 80 grit attached it was fast & surprisingly good at fairing big flat surfaces.
I did hear of a boatbuilder who fitted a longboard to a trackrod swivel & long rod, this was attached to the flywheel of a large slow speed motor, plugged it in & it took the hard work out of it. But as the old engineer once told me "Now we come to the sorry bit, there was no means of stopping it!"

We had a boat come in for a major overhaul and refit, except it wasn't a yacht, or a powerboat, but a 50 ton steel work boat, ex oil fields. The owner wanted the interior turned into luxury accommodation, plus he wanted the deck done in the usual yacht teak planks. Which meant bolting down ply wood, using studs welded to the deck, followed by filler to level, followed by the teak screwed and glued down.

I hired a stud welder, which didn't get enough bite into the deck, so I then had to go round with a stick welder and put a good solid tack on every stud..... hundreds of them.....

The superstructure, the owner wanted it fairing, which presented some major issues as some of it was so far out of true it need 2" of filler to get it 'fair to the eye' as the terms of the contract specified.

The project eventually ground to a halt, lack of funds. I left the company, Yacht Solutions, in 1992 to work offshore. Years later I met an old mate who had been hired to resurrect and recommission this bolide, and I heard it had eventually motored over to the USA.

 

[Keith 66]

Sounds like a boat i worked on, big steel motor yacht It had been built by Toughs of teddington & they had faired it with ordinary polyester body filler. Much of it was coming away from the steel & we used 15 gallons of P40 & 20 gallons of P38 to bodge it up. The previous owner had fitted an mfi kitchen in it & the mdf had gotten damp & blown.
Not the best job i ever worked on!

 

[Morrisman]

Sounds like a boat i worked on, big steel motor yacht It had been built by Toughs of teddington & they had faired it with ordinary polyester body filler. Much of it was coming away from the steel & we used 15 gallons of P40 & 20 gallons of P38 to bodge it up. The previous owner had fitted an mfi kitchen in it & the mdf had gotten damp & blown.
Not the best job i ever worked on!

I wish I could remember the name, but it was an age ago.

The very first yacht I worked on in Yacht Solutions was called Bonito. It had been found floundering at sea, in the Indian Ocean. The skipper was just a skeleton inside, apparently had last checked in by radio to friends 8 months earlier and then died of food poisoning......

The boat had been towed to Singapore and was being recommissioned when I came into the picture.

It's surprising exactly how huge the oceans of this planet really are.

I don't know if there is a register of yachts but it would be kinda nostalgic to know if Bonito is still afloat.

 

[ArAKern]

Well a friend made theses for me. even offered to show me how they work

He works for a company building very high end tender for super yachts.