G&M's 'Drop

[GarthB]

Thanks a lot for the tips Swoody. I tried paint thinner last night, which didn't work very well. Acetone is making pretty quick work of it after scraping everything thoroughly.

Unfortunately, part of this bad batch got used to finish out the back of the roof as well. The 'drop has been out in the sun today to help assist scraping and curing. This area didn't firm up anymore, so I had to pull it off as well, including the third brake light block. As long as no additional surprises arise, everything should be cleaned up by the end of the day today. Just hoping there aren't any tiny random spots elsewhere that I can't find.

The hatch sanded out well, so I'm confident that the epoxy that was mixed properly, cured properly.

Needless to say, the pumps are going in the trash can and I'm opting for either a scale or measured cups from here on out. The medium viscosity hardener takes so long to pump that it gets way too easy to get distracted in the middle of a cup. This will definitely be one of those "chuckle about it around the campfire" stories someday.

[western traveler]

Garth sorry to hear. I had one of those “was that one pump or two” moments when hot coating the underside of my floor. I set it aside and it cooked off in a hurry. Painless of course.
I appreciate you sharing this mishap with us. It is a great reminder for me and others.
Yes, there will come the day you look back and smile at this bump in the road. Like when out enjoying your build.
Swoody is a great guy to have around as are a number of other members.

[GarthB]

A whole lot of peeling, scraping, scrubbing and sanding later, I've gotten all of the bad resin removed, the wood is clean, and we're ready to do the patch work tomorrow. I knew that I peeled away enough glass when it would start to break away from the wood instead of peel. After that, the paint scraper and acetone were used until the surface wasn't sticky anymore. Despite not being sticky, there was still resin soaked into the wood, so I sanded with a 50 grit belt on the handheld belt sander from there until I got back to bare wood. I knew I was at bare wood when my sanding dust got dusty instead of gummy. I had to sand all the way through the face veneer of the plywood in a few spots.




Aside from cleaning up the roof, I had to clean up the TBL block. Part of it cracked off when removing it from the roof, so I had to trim a 1/2" or so off of the leading side. I'll just have to fill the joint with a little more thickened epoxy than before.



Rather than ditching the pumps like I said I was going to, I am going to mark the proper resin/hardener fill lines on a "master" cup. For each cup of epoxy I make, I will compare it to the master to ensure that my levels are correct.

Like Western said, hopefully my mistake will benefit someone in the future. It was a bit of a nightmare when I made the initial discovery.

[noseoil]

Epoxy cure problems can usually be attributed to three things:

1 - Improper measuring: Bad mix due to wrong measure by volume or mass, so it won't combine
2 - Improper mixing: Sometimes the sides & bottom of the container aren't scraped well enough to blend all of the material prior to pouring. Always stir well for at least 2 minutes, too much is better than too little here.
3 - Improper temperature: too cold for the mix to cure correctly, add more heat

PITA to have this happen, but it's part of the learning experience (i.e. why education is expensive in time & money). Hopefully it's not a big deal to clean it up & redo. Live & learn, we've all been there!

[tony.latham]

A whole lot of peeling, scraping, scrubbing and sanding later...

Shit-0-Dear.

Tony

[pchast]

There's another way. Place your mixing cup inside the master cup.
Weigh the first mix per the manufactorer and mark that master cup
as you do.

All subsiquant mixing cups filled inside the master should be good.

[GarthB]

Got the train back on the rails today. I cut a piece of fiberglass cloth for each of the two areas that needed patching. Following Swoody's advice, I left several inches of overlap between the new cloth and the partially sanded glass surrounding the patch area.




Once the cloth was cut and laid out, I wetted out both areas, making darn sure that the mix ratios were correct.



After three or four hours, I checked the curing resin and deemed it was at the right stage for another coat. Instead of using the squeegee, I spread the second coat with a 3 inch foam brush. It distributed the resin very nice and evenly.

I also laid my third brake light back down at this point. Using screws in the block to align with pilot holes that I made in the roof, it was held securely enough to add some micro thickened epoxy to bevel the edges.



At this point, everything has cured up nicely and will be ready for sanding tomorrow. I'm looking forward to getting rid of the evidence of this happening and to begin prepping for primer. I plan to sand, then apply filler where necessary, sand again, apply a thin coat of epoxy, lightly sand, and then prime.

Thanks again for all of the advice and words of encouragement everybody. I feel blessed that I didn't need to tear the roof apart.

[GarthB]

While waiting on epoxy to cure, I got the cooler tray fixed and temporarily mounted on heavy duty slides to check for any fitment issues. It rubs slightly on the floor on one corner, so I need to go back and do a little sanding. Aside from that, I'm happy with how it worked out.



After the cooler tray, I moved on to constructing drawer boxes. This was a pretty enjoyable, relaxing task. Tony was spot on with recommending Jay Bates' drawer construction technique. It's a quick and simple method that works. I'll add the drawer faces once I've gotten the slides mounted.



The box on the left is the upper drawer of the middle bay. The center box is the lower drawer of the middle bay and is shorter in order to account for space for the battery. The box on the right is a shallow drawer that will be mounted above the cooler. It should work well for utensils.

Feels good to be getting into the home stretch. A couple more weeks of work and it'll be a full-fledged 'drop.

[cjlangellier]

At this point, everything has cured up nicely and will be ready for sanding tomorrow. I'm looking forward to getting rid of the evidence of this happening and to begin prepping for primer. I plan to sand, then apply filler where necessary, sand again, apply a thin coat of epoxy, lightly sand, and then prime.

Thanks again for all of the advice and words of encouragement everybody. I feel blessed that I didn't need to tear the roof apart.

Nice save Garth! I’m positive I’ve learned more from the mistakes I made in my trailer than from all the things that went to plan.

I’m going to follow the same method as you did for the galley drawers. Hoping I can knock out the cooler and stove drawers before Saturday.

[tony.latham]

Got the train back on the rails today.

Do you think it was caused by a pump failure?

Tony

[GarthB]

Got the train back on the rails today.

Do you think it was caused by a pump failure?

Tony

I don't believe so since the rest of the roof and the hatch cured properly. I think it was completely my fault. After a little reflection, I think that the two biggest lessons learned were this:

1. Having a helper for a fairly large fiberglass job is a great asset. However, if you trust them enough to help, you need to trust them enough that you aren't always turning around to see how they're doing. I knew full well that my wife knew what she was doing because she did a great job on the walls, yet I continued to check on her constantly. Focus on your own responsibility. There were two cups of epoxy that I set aside during this job because I turned around to see how my wife was doing and if she needed help and when I turned back to the pumps, I wasn't 100% confident in where I was at with the mix. One of these cups cooked off just fine. The other didn't cure properly and I'm thankful that I didn't use it.

2. Take. Your. Time. Going into fiberglassing the roof and hatch, I didn't have a good feeling. I didn't know why, it was just a gut thing. Looking back on it, I had this feeling because I knew we were trying to do more than we really had time for. We wetted out the cloth around 8:00pm and we laid down the second layer of epoxy at 9:30pm because we didn't want to be up too late. This should've been a weekend job so that there was more cure time between layers and we didn't feel rushed to get it done. Had we not been in a hurry, I may have avoided a bad mix ratio.

[tony.latham]

[img]Had%20we%20not%20been%20in%20a%20hurry,%20I%20may%20have%20avoided%20a%20bad%20mix%20ratio.[/img]

Gotcha.

Randall White had the internal portion of a pump loosen and cause the same issue:



He managed to get it off and do the fix.

Tony

[GarthB]

Spent the whole day sanding the 'drop head to toe and buried all evidence of ever having the epoxy nightmare. I gained a new level of respect for the folks doing bodywork for a living. It definitely requires some elbow grease, even with fancy sanding equipment.




I sanded pretty aggressively using 60-grit on the random orbital. The walls had a whole lot of epoxy on them, so I didn't get anywhere near the cloth. The roof had less and I got down to the cloth in a couple of areas. In one of the spots where I had overlapping cloth, I accidentally burned through both layers, thinking that I hadn't yet gone through the top layer. It was a small spot so I'm not overly worried about it.

I will be rolling on two thin coats of epoxy after the filler, so everything should be pretty well protected.

After all of the sanding, I went back and did another round-over of the wall/roof joint. The 1/4" round-over wasn't quite as noticeable or as smooth as I wanted, so I went with 3/8". It's a lot smoother of a line now that the router had a much flatter surface to ride on.

[swoody126]

GB, go ahead and feather that spot and lay some cloth over it

the plywood's achilles' heel is bare wood

the cloth aids in preventing plywood checking which is where moisture invades

the cloth fibers drastically reduce the chance of that happening

you wont be sorry to have invested the extra day ±

if you lay it early in the morning you can 2nd coat it that evening

small spots like this is where faster hardener comes in handy(otherwise i like SLOW & TROPICAL SLOW)

if you don't you'll always wonder ...

i have worn out the finger tips of my elk skin gloves block sanding my screw up patches and don't regret it

IMG_4708.jpg (877.45 KiB) Viewed 422 times

sw

[GarthB]

I really appreciate all of your advice Swoody. You and others have definitely had some wise suggestions! I’ll make a small patch.

Is there any reason I should be concerned about where I got to the cloth but not through it? The whole thing will for sure be getting two more thin coats of pox.