Lifting roof XPStream - Almost Finished!

[OP827]

Just looks like it didn't cure for a long enough time. If the paper's clogging like that, the surface was too soft, or heat from the sander softened it too much. Let it sit longer & see what you get. It might need to cure for a day or two or need more heat for it to kick off better (just bring the panels down here for an hour or two & it will be cured fast). Looks really nice!

- thanks for the offer and good information!

[OP827]

It looks great and a heck of a lot of work. Would stearated sandpaper help reduce the clogging? I have not done any epoxy work to speak of, but it sure helps when sanding polyurethane.

It is all relative, Glen. Yes building fold-able and big trailer like this could be somewhat more work than simpler shape trailer, but this is my first trailer build, so I cannot judge. It is not a lot of work to fair and sand, the sander works pretty fast. I sanded the epoxy , the whole roof for less than an hour and changed only one paper disk, could have finished with just one sand disk easily. Applying the filler was a bit more time and work. I know nothing about stearated sandpaper, does it have some sort of dry lubricant? If yes, I am not sure about how good then the primer/paint will stick to the sanded surface after that.

I think I'll bring the roof out to sun today as per Noseoil's tip, that will make sure it cured as this filler most likely hardens from UV rays pretty good. Pictures to follow.

[OP827]

Went out to get some sunshine, where is a good spot?
The wind started to really pick and the panel started rocking, wanted to fly, had to bring it back inside.

[OP827]

Wind did calm down and after the panel sat for about half hour in the sun it feels that the sun started to do its job by hardening the filler, almost no clogging and so much easier to sand . I'll keep it for another few hours in the sunshine before going back to sanding. Cheers!

[WoodSmith]

Yes stearated sandpaper has a dry lube in the paper to help prevent corning. Again, I have virtually no epoxy experience, but it is fairly standard to use in finishing woodwork when sanding between coats. Aluminum oxide paper that has the grey (gray?) color is usually stearated. I think that as long as you wipe down after sanding, which you have to do to get rid of your dust anyway, you will be good to go. Hopefully an epoxy master will stop by and educate both of us. Attahoekid maybe? Didn't he epoxy coat?

[OP827]

Yes stearated sandpaper has a dry lube in the paper to help prevent corning. Again, I have virtually no epoxy experience, but it is fairly standard to use in finishing woodwork when sanding between coats. Aluminum oxide paper that has the grey (gray?) color is usually stearated. I think that as long as you wipe down after sanding, which you have to do to get rid of your dust anyway, you will be good to go. Hopefully an epoxy master will stop by and educate both of us. Attahoekid maybe? Didn't he epoxy coat?

Thanks for information, appreciate that. I think I am now past that "sticky-tacky" point in my build. Next time I used this filler, I will be much more carefull with the mix hardener, making sure I got enough of it and the mix is thoroughly prepared.

Yesterday the filler hardened enough while put outside in the sunshine to not to be a big problem. I managed to finish filler sanding on the ceiling then turned the roof over. Today I plan to add two more epoxy coats on it and work on other things, preparing for the walls final assembly/glueup.

EDIT: found this article about epoxy contamination that also mentions stearated sand paper http://www.westsystem.com/ss/assets/Uploads/Ew20Contamination.pdf

[OP827]

After I turned the roof over to work on exterior side I am puzzled whether I got any amine blush on the surface as I did not finish the lamination with second and third coat while the epoxy was still "green", being new to large surfaces lamination, I did not know better at that time. Now I washed its rough surface with water the best I could as per West Systems article recommendations (http://www.westsystem.com/ss/assets/Uploads/Ew20Contamination.pdf), but the water still beads on the surface as if it is still contaminated according to the article test.. , but it looks clean and there was nothing in the shop that could contaminate it, except as I mentioned the "potential" of amine blush appearance on the surface due to air moisture. Air in Alberta is 50% relative humidity or less usually.
I think I would go ahead and fill the weave with second and third coats of epoxy as is, I did everything I could to clean it.
Maybe Atomic77 will help with advice, I sent him a PM on this.

[KCStudly]

Maybe a plastic bristle scrub brush or scouring pad (greenie) to get into the pockets of the weave? Did you use plain water or soapy water to wash?

[OP827]

I did wash with scotch brite like pads and clean(non-soapy) water as West System recommends, but as you can see due to high weave, it is practically impossible to scour and reach the surface's low points, the the scouring pad would not reach inside those little valleys in the weave, maybe I shall use a brush instead, but I am not really positive that I do indeed have this amine blush. I used East System epoxy with 834 hardener, some sources say it is non-blush hardener, but some reports does say the blush is there, so I am not sure here.

[dales133]

Hey OP i just read your whole build thread and this is a realy cool innovative design.
Quite ambitious to but you seem to be getting on top of it nicely.
I dont know if youve ever seen the A vans made in australia they are fold down roof and walls and while quite different might help you with some sealing and hardware designs/selections.
Definatly be keeping up with your build now....im just sorry i missed it earlier,i realy like the different stuff

[OP827]

Thank you kindly Dale. I got aware of Avan trailers in Australia while I was looking all over the web for ideas. My folding design represents a challenge, but this is what I like about it. It keeps me awake at night sometimes how to do foldable design yet keep it reliable and simple to use. Anyway, long story short, will see how it turns out. I'd say that inventing a thing/idea is an easy part, when making the idea really work is a harder part and this is what I am doing now.

More pictures: roof is turned over, coated with two more coats of epoxy to completely fill the cloth weave and now starting long board sanding and fairing while it is easy to access.

I feel now that the beam/sparless roof design is working, the roof is sufficiently strong and rigid, no additional stiffeners or spars should be required. It feels light so far when lifted from one end, I will probably take a bathroom scale and take a three-point weight.

[dales133]

Looks awsum.
I hear you on the turning plans into reality thing.
I dont think ive slept properly since i started mine (hence the fact its 3.57 am and ive been awake hours)
Keep up the good work

[OP827]

The roof panel weight so far is 11.5 (front)+12.5(back) = 24lbs as per bathroom scale. Not bad at all. It will be added with the sides and front parts, but those foam parts are much smaller than the roof. Will keep wood and plywood reinforce embeded pieces to a minimum, only where its needed to keep the weight in check.

[dales133]

24 lbs is good.
My hatch ribs weigh 30 lol

[OP827]

24 lbs is good.
My hatch ribs weigh 30 lol

I hear you, it's Wood vs. foam/FG. Your hatch is way much stronger though.

CORRECTION EDIT: The bathroom scale was in kg, so it is 24kg which is 52 lbs. Not bad anyways, it is easy to lift.