Lightweight panels for camper van

[Caddyshack]

Hi All, I have a 7.5 tonne horse lorry with a kitchen, living area, beds and shower etc…the weight is quite high and I want to reduce it.

Ideally I would replace the outside locker doors which are 10+mm thick Grp covered ply with carbon fibre along with the ply in the seating areas but that is really expensive in large sheets with any thickness for strength. I have seen some building panels that are very thin honeycomb insulated sheets but the companies cannot tell me if I can replace ply like for like.

Is there anything anyone can suggest? I am swapping the backs of the locker boxes from 12mm ply to moulded fibreglass which seems a lot lighter but the door fronts are still heavy.

The seating area turns in to a bed and that is 12mm ply covered with carpet, there must be a lighter solution?

These are the locker doors:



You can sort of see the seating area on the right in this pic below. I also want to replace the heavy kitchen chip board work surface with something, any suggestions for that?

Edited by Caddyshack on Tuesday 4th October 19:49

[Super Sonic]

Alloy wheels. Rotating mass and unsprung weight. Increase acceleration and improve roadholding. Are you going to take it round a track?

[Caddyshack]

Super Sonic said:

Alloy wheels. Rotating mass and unsprung weight. Increase acceleration and improve roadholding. Are you going to take it round a track?

Alloy wheels are a thing for lorries but about £1000 a wheel and I have 6.

The 7.5tonne is the max carry weight including the lorry and it is easy to hit that once you have a horse or two in the back. I need to get the weight down as the coach builder went for luxury and I am close to the legal limit with 1 horse in the back. By the time you start adding 100 litres of water for the shower etc it gets a bit risky.

Track days would not be fun with the 56 mph limiter but I reckon I could drift it a bit.


It’s on air ride too so I can slam it in the weeds man! (Well drop the back so the horse can get in easily but the VW boys would love it)

[Bill]

Have they just used normal kitchen units?? You can get lightweight ply for camper builds. Maybe aluminium for the doors, it's much cheaper than it used to be.

[dhutch]

I can't see replacing a few locker doors making any significant impact on the overall weight, even if the replacement material was weightless all the doors combined can't be more than a few 100kg? I really doubt the grp skin is actually 10mm+ thick. Then you have to make it all look nice again and fit it with the rest of the van.

Refitting the interior might be more practical, but it's not going to come cheap.

Can you not fill up with water in arrival?

[Caddyshack]

dhutch said:

I can't see replacing a few locker doors making any significant impact on the overall weight, even if the replacement material was weightless all the doors combined can't be more than a few 100kg? I really doubt the grp skin is actually 10mm+ thick. Then you have to make it all look nice again and fit it with the rest of the van.

Refitting the interior might be more practical, but it's not going to come cheap.

Can you not fill up with water in arrival?

100kg would be a nice saving. The Grp is coated over the top of 10mm ply, they are really thick doors.

Yes, I do fill up when I arrive if I know there will be water there but I need to carry some as the horse must have water and some places are not set up well, you can have hundreds of people competing and one low pressure tap.

I can save around 100-150kg as it has heavily over engineered horse partitions

They are regular kitchen units and I am working on reducing the weight there.

The locker doors are 10-15 kilos per locker and there are 9 of them, if I can save 50 kilos there plus what I can on the back of the actual lockers I might get another 100-150kg or more off…it all adds up, if I can save 300kg overall it would be a massive improvement. Our horse weighs 430 kilos!

[Caddyshack]

Bill said:

Have they just used normal kitchen units?? You can get lightweight ply for camper builds. Maybe aluminium for the doors, it's much cheaper than it used to be.

Yes, looking at those options. There are not that many kitchen units to be fair but I think I can save a bit there.

[WelshRich]

I self-built a camper a few years ago and joined a site called SBMCC (self build motor caravan club) - It cost something like £15 in subs IIRC, but worth every penny for the advice from some really helpful posters.

Vohringer was the go-to for lightweight ply but not cheap. People typically made up wooden frames and skinned them with 3mm facing sheets rather than use solid ply where strength wasn’t required.

You might be able to “add lightness” to the existing materials like the seating area/worktop by taking it off and using a router to create grooves/pockets on the underside in strategic areas.

I didn’t use it myself but they also talked about using Dibond composite aluminium panels (like the stuff that motorway signs are made from) to create external doors/lockers.

[Caddyshack]

WelshRich said:

I self-built a camper a few years ago and joined a site called SBMCC (self build motor caravan club) - It cost something like £15 in subs IIRC, but worth every penny for the advice from some really helpful posters.

Vohringer was the go-to for lightweight ply but not cheap. People typically made up wooden frames and skinned them with 3mm facing sheets rather than use solid ply where strength wasn’t required.

You might be able to “add lightness” to the existing materials like the seating area/worktop by taking it off and using a router to create grooves/pockets on the underside in strategic areas.

I didn’t use it myself but they also talked about using Dibond composite aluminium panels (like the stuff that motorway signs are made from) to create external doors/lockers.

Thank you, some great advice there, I will join up if they are still going. I have thought about breaking out the router and getting busy.

Edited by Caddyshack on Tuesday 4th October 21:21

[Caddyshack]

Today I took the first locker out, it was 38 kilos. I also took off 3 kilos of wasted metal which had not been cut off as short as it could have been without affecting any structure. The replacement locker is 8 kilos.

Looking underneath there are load of areas where the coach builder used excessive metal. The calor gas bottle holder is made from 1 inch box section and has more gussets added.

[dublove]

Composite sandwich panels....

Honeycomb core, foam core, with aluminium, glass fibre, ply skins. Makes for a very light yet very strong panel.
https://www.honeycombpanels.eu/en/products/sandwic...

[Caddyshack]

anonymous said:

[redacted]

Odd thing is, I can tow it behind up to 750kg and that is ok???

[Caddyshack]

dublove said:

Composite sandwich panels....

Honeycomb core, foam core, with aluminium, glass fibre, ply skins. Makes for a very light yet very strong panel.
https://www.honeycombpanels.eu/en/products/sandwic...

I think those will do the job nicely…many thanks.

[MDMA .]

We buy a huge amount of product from Koskisen in Finland. They do a product called Kore. Not sure if you can buy it from a supplier or not. Our product has its own brand name (same as Kore). Quite expensive though.

[Caddyshack]

MDMA . said:

We buy a huge amount of product from Koskisen in Finland. They do a product called Kore. Not sure if you can buy it from a supplier or not. Our product has its own brand name (same as Kore). Quite expensive though.

Thanks, I will have a look.


I have saved a fair chunk already. Quite surprised how I filled 3 small buckets with steel off cuts from redundant brackets, bolts that were too long, 1 inch steel sections that were miles too long etc.

The horse partitions are 150kg heavier than the new ones I have found (total).

[dhutch]

I remember a guy talking about prep'ing an autotest car. This included drilling 2inch holes in lots of the cars body, area around door reveals and boot hatch etc which are unseen when the door/hatch is shut. Both door and frame, oft areas that are two skins thick. He said they filled several buckets, and once full you couldn't get them off the ground!

[Caddyshack]

dhutch said:

I remember a guy talking about prep'ing an autotest car. This included drilling 2inch holes in lots of the cars body, area around door reveals and boot hatch etc which are unseen when the door/hatch is shut. Both door and frame, oft areas that are two skins thick. He said they filled several buckets, and once full you couldn't get them off the ground!

Yes, it all adds up. My friend has an Alfa like the alfaholics ones and soooo much has been drilled it is amazing to see. It feels like you are pissing in the wind on a 7t lorry to begin with but I have noted all the weights as they come out and it soon goes over 100kg and I am hopeful to get in the 300-500 range in total with all the panels etc.

[48k]

By far the biggest weight in the 7.5 tonners is the floor. The largest weight saving is to replace the wooden floor in the horse area with aluminium. Actually not as drastic / big a job as it sounds. You also end up with a stronger and longer lasting floor that won't rot. Do you know if yours has been changed?
Our DAF 45 with ali floor has a payload of 1.5t.
I'd be reluctant to scrimp on partitions or bulkheads - a pair of half ton horses will have a lot of inertia in an accident.

[Caddyshack]

48k said:

By far the biggest weight in the 7.5 tonners is the floor. The largest weight saving is to replace the wooden floor in the horse area with aluminium. Actually not as drastic / big a job as it sounds. You also end up with a longer lasting floor that won't rot. Do you know if yours has been changed?
Our DAF 45 with ali floor has a payload of 1.5t.

I went to see a lorry builder who said the same. I didn’t think the reinforced ally felt all that light but I need to check if ours is 3/4 ply doubled up as if it is each 8/4 sheet is 30 Ish kilos so I can compare that to the ally.

Our living is single 3/4 ply.

1.5t payload is impressive. I assume it didn’t have huge living?

I can see that it wouldn’t be all that hard to swap the floor. It looks like our hydraulic tailgate has been well over engineered too.

I was talking to a guy who had just weighed a brand new Oakley supreme and he said the payload was under 300kg after all the fancy stuff had been optioned.

[48k]

Caddyshack said:

48k said:

By far the biggest weight in the 7.5 tonners is the floor. The largest weight saving is to replace the wooden floor in the horse area with aluminium. Actually not as drastic / big a job as it sounds. You also end up with a longer lasting floor that won't rot. Do you know if yours has been changed?
Our DAF 45 with ali floor has a payload of 1.5t.

I went to see a lorry builder who said the same. I didn’t think the reinforced ally felt all that light but I need to check if ours is 3/4 ply doubled up as if it is each 8/4 sheet is 30 Ish kilos so I can compare that to the ally.

Our living is single 3/4 ply.

1.5t payload is impressive. I assume it didn’t have huge living?

I can see that it wouldn’t be all that hard to swap the floor. It looks like our hydraulic tailgate has been well over engineered too.

Our living is toilet cubical then a sink, fridge, burner and microwave. Table in the middle. Mattress in the luton. Nothing mega. And no hydraulic tailgate It's an ex John Lewis delivery truck. I'd definitely investigate the floor before you start messing about routing holes in worktops and things because it's potentially a (relatively easy) win.

Another relatively-easy-but-expensive win is to replace your lead acid leisure batteries with lithium batteries which saves 10-12KG per battery.

Caddyshack said:

I was talking to a guy who had just weighed a brand new Oakley supreme and he said the payload was under 300kg after all the fancy stuff had been optioned.

I can well believe it. It's actually frightening when you read lorry adverts for 7.5t saying they carry three horses, or see them at shows with all the bells and whistles on, 3 people, 2 horses, tack lockers, massive water cannisters, etc..... I'd guess 90% of lorries at events are overweight. People are either naive or just deliberately ignoring the law.