Silkaflex 252

[mmmc101]

I am ready to install the .050 alum on the front of my box.(before I put the box back on the truck) What surface prep is required to get the proper bond using Silkaflex 252 ? The framework is primered. Does that need to be stripped ? Are there any tricks to using this stuff or tips I need to know ? I have never used any adhesive before,only screws. I still plan on screws at the seams. Does that need to be glued as well ? Any input would will be appreciated.
MMM

[Bob86ZZ4]

I'm not sure if you need to screw too. My truck is made using all dlued panels, no screws. I found this: Sika Sikaflex-252 One Part Polyurethane Adhesive White 10.5OZ - Sika Corp. - SEALANT

Maybe that might help?

[Bob E]

The outer skins on my truck are .050 alum & originally installed with 3M VHB bonding tape with no screws or rivits.. Before I started on the interior, I had a couple seams come loose. I bought a pneumatic calk gun & 18 tubes of sikaflex 262 and forced it betweeen the sides of the (structure) square tubing & the aluminum skins, then used my finger to further force it into space (btwn the sq tubing & skin)
I've not had any further problems.
Prior to applying the sikaflex to the structure of the truck, I took a piece of scrap tubing & aluminum skin and laid a 1/2" X .040" ribbon of sikaflex ibetween them. A day later, I couldn't pull the alum skin loose without destroying it. If I were to do another conversion, I would definately use sikaflex. I believe it would hold better than anything else but still allow for expansion & contraction of the outer skins, as it remains somewhat flexable even after it has cured.
I researched the 252 product & found that one of it's uses is in the manufacture of commercial truck bodies.
You will need to clean all surfaces of paint, primer grease, oil, etc, . . . According to most sources I was able to find, it bonds best to clean metal, plastic, or ??
Yes, it's a bit expensive, but you DO NOT want problems after you close up access to the inside of the structure.

[mmmc101]

Thanks guy's for the input. I have elected to put screws on the seems only to match the trailer I will be pulling. When I ordered the trailer it was supposed to be "screwless". However, I had them add 24 inches to the height of the trailer. The factory called me and said they would not build it without screws on at least the seems on any trailer above eight feet due to the amount of flex the trailer would have. Made since to me. My sidewall sheets are almost ten feet. Now if this snow will just stop,maybe UPS can run and bring me the Sikaflex I ordered!
MMM

[blizzardND]

I didn't use it but was told when I bought 2 cases of Silkafelx in Elkhart that they put the tubes in a cooler with a trouble light to warm them up so they flow really nice and consistant. I gave those to the guy that welded my truck, he used 3m tape on my build and I never saw the boxes of 'flex after that.

blizz

[mmmc101]

I installed the first alum sheet on the front of my box 1 week ago. I followed the manufacturers instructions to the letter. All surfaces clean and free of oil ,dust,grease etc. I lightly scuffed the the primered framework with scotchbrite. The sheets were clean and dry. I also did a test panel on some scrap tubing/sheetmetal. According to the chart, curing will take between 4-7 days depending on temperature and humidity. After 4 days I was able to pull the test panel apart rather easily. The sikaflex bonded to the tubing but not to the sheet. The sikaflex was still soft like caulking. Did I do something wrong or was it just not cured yet ? My shop stays at a constant 65 degree's. I do not know the humidity but I suspect it is quite low. Could that have been a factor? The bonding to the tube was very good. There was no bonding to the alum sheet at all. Any thought's on what went wrong or am I just to impatient? Michael

[dgorila1]

A question regarding installation using SikaFlex: ater the panel is glued and placed should some type of pressure (clamps, strongbacks, etc) be put against each joint until the sealent cures for a better bond?

[volvoman]

did sikaflex ever dry . did you have to do any thing different? how did you hold it in placed till it dried.

[mmmc101]

I used 2X4's and C-clamps to hold in place for several days to allow plenty of time to cure. I am using sikaflex and screws on the seams/top and bottom. I guess it bonded OK as none of the sheets fell off when I removed the clamping. I have ony sheeted the front of the box. Will let you know more when I do the sides and back. Michael