Another problem for the experts

[walker]

Since you all did such a great job with the engineering problem.....I have another on for you.

The sides on the camper are going to be 600mm high. I am building a frame and then 1.5mm steel sheets will attach to the frame. The entire tailer will be enclosed in (including top) with no drop down sides or ends. Access will be via a hatch on each side at the front and a kitchen will slide out of the rear. This is to try to help with dust proofing.

The problem - Should I weld the sides, floor and top onto the frame or pop rivet?

No matter what I do I will sikaflex the panels on as well but I have herd before that pop riveting is better because you need to allow flex in the body.......but it would be a lot easier to weld.

I was thinking maybe short 25mm welds followed by a gap then another weld???

[seqfisho]

Adam,

I would go the stitch welds as pop rivets will eventually wear and break with the vibration over outback roads.

[landrovermick]

yes but pop rivits are easier to fix on the side of the road....

[seqfisho]

yes but pop rivits are easier to fix on the side of the road....

Yes but if you weld you wont be stopped on the side of the road and need to fix them:p

[walker]

Does anyone know what they do on the "expensive" off-road campers like Kimberly etc?

[chunk]

your best option is to weld, even slight flexing of the frame will cause the rivets to break.

P.S. im looking forward to see the finished product. so keep the photo's coming and dont forget to keep a good set of plans, you never know who might want to use you design. :D

good luck.
jeff

[walker]

I did start with a great basic set of plans and drawings which I posted somewhere here. Then when I started building it all went out the window and now I make it up as I go.:o

Put I will re-draw them and post it up

[Blknight.aus]

Mate I noticed you have what looks like a fancy dancy mig welder there :) (your other thread)


I would be spot welding it on using a saw tooth pattern then running a bead of selastic along the inside of the join.

best of both worlds the ease of repair of rivits (drill out the weld then insert rivit) and the strength of welding...

Im not entirely sure but your welder should be able to do spots with the right attachemend which, I would think, you should be able to hire from a reputable welding supplier, but they will sting you for the electrodes in the attachment... ($40ish a pair from memory)

[walker]

Thanks Dave, I will look into it.

The welder is Dad's. He works for himself and makes metal shopfitting products so he has a few welders and 3 spot welders but the spot welders are all fixed position.

[stusgonesailing]

I was given some advice by a guy that rebuilt a 101FC into a camper that the best thing for sealing panels is not sikaflex or equivilant but coachbuilders sealing tape. Apparently it is a double sided tape with a glue in it that when fitted can only be removed with a grinder.

Apparently it is what all the bus/coach bodies are put together with. Seals all the joins and remains fexable so it keeps on sealing.

[walker]

If anyone else is interested, here is a great site about spot welding using a MIG welder. Main problem is you need a good MIG with minimum 200A.

http://www.esabna.com/EUWeb/MIG_handbook/592mig11_1.htm

I think I already have one of those special tips so i will give it a test tomorrow and see how it goes. If it works it should save a lot of time.

If it does not wrk then I think I will use plug welds to attach the sheets.

I have heard about that sealing tape but I want to use the sikaflex as it is easier to put on and I am using it more as an adhesive than as a sealer.

I will silicon up all the inside for sealing.

[mr_sav]

Does anyone know what they do on the "expensive" off-road campers like Kimberly etc?

For the Price, I dare say they are gold plated.

[Buggerluggs]

Adam,

Kimberly use a moulded plastic liner which they stick to the tub and sandwich between the top rail and canvas. Theres a good description on their web pages. Bit over the top for a home made job.

[matbor]

what about using one of these to do the job :D :D ....

http://www.dansworkshop.com/Homebuilt%20arc%20welder.shtml

[walker]

Again on the topic of attaching the body panels to the trailer.

Has anyone had any experience with Sikaflex?

I was told that I should be able to fix on the steel panles ONLY with Sikaflex. I sent an email to the technical department with all the details of what I was doing and using and they have replied that there would be no problems using Sikaflex without rivets or welding. They recommend using Sikaflex 252.

I am sure they are right but it just doesnt feel righ not welding on the steel panels. But if I can do it it would be a lot neater and easier. I also read somewhere that it is better because it allows the panels to flex a bit and stops stress cracking.

[disco_ute]

if u are going to use sikaflex then don’t spray that tub liner stuff i used as it dries rock had and will crack apart if any movement!! When i was looking for work utes i noticed all the tubs had some sort of sikaflx type stuff between them... maybe contact a few panel beaters and ask them what they use between the joins of body panels inarticulate tubs o utes an then IMO I would pop rivet and or weld them just t be safe!!

[86mud]

Check out this site http://www.robgray.com/motorhomes/index.htm

This mad guy build an unbelievable motorhome. He used aluminium checkerplate attached by rivets and a 3M brand tape double sided tape...

I used the same process on my off road trailer. But I did have a few rivets crack on the Plenty Highway....just carried the rivet gun a few rivets in the tool box.

Cheers

[spudboy]

Wow - That RobGray truck is something else! Not sure that he's going to get $350K for it, but I can see that he;s spent a bomb on building it. Good work.

[harro]

yes but pop rivits are easier to fix on the side of the road....


Sikaflex for the seal and steel pop rivets for the join.

They are a side of the road fix.

[walker]

Yes they are....but I don't like pop rivets. I think I will stick the panels on with Sikaflex which should be ok on it's own but then add some spot welds as well.
If I carry a battery drill and pop rivets I can still do a side of the road fix.

[walker]

I found this data sheet for sikaflex 252. The application seems perfect for what i want to do. I was also interested in the tensile strength. Unfortunately the numbers mean nothing to me, are there any engineers who can tell me if that is a good tensile strength (600psi)

http://www.sikaindustry.com/tds-ipd-sf252-ind-us.pdf#search=%22sikaflex%20%2B%20adhesive%22

[Buggerluggs]

Hi Adam,

We use this stuff like its going out of fashion. We use in on our fridges because it remains elastic even in -25 degrees. We also use it in our hot chicken cases for the same reason, but when hot as well. In terms of tensile strength its academic really. I know that if you clean the surfaces properly before application (there is a special primer as well, but we do not use it), you will not be able to separate the two panels. Our Frigies have to use knives to cut through in order to separate panels and this is after 15 years of service. The only thing you need to remember is that surface area is where the strength comes from. I tell you what I would put this stuff up against rivets any day (no rivets!)

Just as a matter of interest we used one of these sorts of products as a 'living hinge' application for one project. Worked extremely well.

[walker]

Thanks Ian, that what I wanted to hear.

The tech guy that eamiled me also told me of 2 other products I should be using before applying the sikaflex. One is a cleaner and the other a primer. He said the same as you, if you use the product as stated with the primer you will never move it without cutting.

As for surface area, that could be my downfall. The larger panels will be 1800x600. There is a 50mm frame around the edge and i will have 2 25mm studs at equal distances along.

[Buggerluggs]

Thats plenty of area! You should not have any problems.

[Buggerluggs]

Just another thought. I used Sikaflex on my rock rail/side steps. I applied a single bead inbetween the rocker panels and the rail. I had to do some work on the rails to add a checker step surface so had to remove them, This was a bloody nightmare. I removed all the screws I had used and tried to pry the bar off. It just would not move. I jumped on it, jacked the car up with it, stuck knife blades in between to try and pry it, all to no avail. I ended up having to painfully slice through between the panels until all the skaflex had been cut through. So for what you are going to do, not a problem!

[walker]

:D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D


So now that I am not welding anymore, it's a pity I have these 3 sheets of steel.......I could have used aluminium.

Then again, I need the weight or I am not going to get anywhere near close to the spring rating.

Looking forward to bouncing around some ideas at Cupweekend!