Sleeper for Tacoma

...ask your questions in the appropriate forums BUT document your build here...preferably in a single thread...dates for updates, are appreciated....

Re: Sleeper for Tacoma

Postby woodslanding » Tue Jun 01, 2021 9:11 am

OP827 wrote:Hi woodslanding!
I found that filling small voids with GS was not working great for me with more voids inside the GS after cure and it does not sand the same as foam.
It seems better to fill small voids before glassing with micro balloons and epoxy mix/slurry and right then lay the glass cloth similar to how Rutan moldless aircrafts were built.
I have not used GG in my build, I used PL Premium for wood and foam with good result, but clamping is needed as PL Premium, same as GG is expanding while curing from moisture in the air.
If you need to lay FG in tight corners around your windows you can brush epoxy and let it cure to be close to become non-sticky and then lay FG cloth in those areas. If FG does not stick you can carefully heat epoxy with a hairdryer or hot gun(carefully not to melt the foam) to make it sticky while warm again. Once surface is cooled but before fully cured you can then brush fresh epoxy on the glass cloth to laminate. Another known method is to use a very light spray single pass of 3M contact spray glue just to stick the cloth and then impregnate the cloth with epoxy, but I like the first method above better due to a full epoxy strength in the cloth with no contamination.

Hot wire will work on EPS and XPS foams, but will not work on GS polyurethane foam (and create poisonous fumes).

There is some good information in Moldless Composite Sandwich Aircraft Construction book by Burt Rutan.


These are all really great tips, thanks!

IIRC, you mentioned using dollar store wrapping paper as peel ply. Is this right? I'm trying to imagine transparent wrapping paper! Do you have any more details about that method? I like the idea of getting a good surface with peel ply, but haven't been able to find much on the web about using it with hand layup....

>>>EDIT: This stuff? https://www.amazon.com/Cellophane-100Ft ... 89&sr=8-18
and found this useful thread: https://www.boatdesign.net/threads/peel-ply.14461/
they suggest this: https://www.homedepot.com/p/3M-6-ft-x-9 ... /202975037<<<< That's pretty cheap!

I would think the foam has plenty of give, so I don't see the need to do foam work on the truck.... (I have done one test assembly to get the angle against the cab correct.)

Not so with the FG! Putting the FG on while mounted to the truck seems challenging (it's 4wd, and up high!) but I'm wondering about doing the first round of FG, and then moving it to the truck to let it cure. I'd think it would still have enough give at that point to sit flat.

thoughts?
Last edited by woodslanding on Tue Jun 01, 2021 10:02 am, edited 2 times in total.
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Re: Sleeper for Tacoma

Postby woodslanding » Tue Jun 01, 2021 9:21 am

In other news, fiberglass, carbon fiber and epoxy came yesterday. I'm now up to over $500 in this thing. So I reckon I better finish it ;)

Parts list:
fg $100, cf $75 from composite envisions, $200 total after shipping. Could have saved $$ by going all fg, but I want to experiment with cf too.
raka epoxy from raka $130 shipped... may have to get more, we'll see how far this goes.
doors and windows $100 (could probably have talked him down, but they were in such good condition...)
foam $100, 3 sheets, in soothing blue. HD was all out of pink in this thickness. Probably move to 1.5" for the big build.
plywood, 1 sheet $65 (wow, did this used to be cheaper. but when I think what it takes to make a tree, this still seems cheap!)
panopoly of adhesives, fillers and various small specialty tools which may or may not ever come in handy, est. $100

I have a bunch of fine trimming/fitting to do today, and then I'll start gluing. I still haven't figured out the roof, but I decided it's going to be easier to do that when the walls are in place. The test assembly isn't really strong enough to hold the roof (ask me how I know!) so I will have to foamprovise.

I'll start with just the first level. After experimenting with both GG and GCA, I have more faith in GG, and by not moistening it, I'm hoping it will not expand too much. I'll limit the glue to the inner half of the surfaces, (except where bonding to the plywood) and fill afterwards from the outside with cabosil after sanding. I'll tape the inner seams against overspill, and put a lot of tape on the exterior for clamping effect, (but not ALL along the outer seams so some moisture can get in there for curing.) I don't have a ton of clamps, but these 45 degree angles don't really clamp well anyway.... I can clamp the sides that have window cutouts to the plywood no problem.

unless someone sees an issue there....

Onward and Awkward!
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Re: Sleeper for Tacoma

Postby OP827 » Sat Jun 05, 2021 7:59 pm

I used a transparent gift wrap from a dollar store trying to find a method to cut on FG finish times when making doors and hatches. I think it worth trying to experiment with, but need to be careful not to starve the lamination especially when fiber glassing over plywood. I was using squeegee to push out bubbles and could have pressed a little too hard, needed to leave more epoxy in the cloth. Dry plywood will suck epoxy and may leave glass dry and this is what happened with some of my work on Baltic birch plywood. Thanks for these links, I looked there and found this John Blazy's article there that is very similar to what I did with gift wrap thin film, but the John used a much thicker film, 30mil and that must be the game changer here. Sometimes my gift wrap film would not want to peel off, but I think it was because the epoxy was not yet fully cured and I was trying to rush with peeling it off. A thicker Mylar film could work better, from the chat it looks like proper name for that film is "Polyester PET". I still think that getting a bubble free laminate with this method could be challenging on large surfaces. I could not explain sometimes why bubbles were reappearing under surface, could be porous plywood. But it's worth trying and it saved me a lot of time for the doors and hatches finishing. But again your personal results might be different than mine.

Fiber glassing the shell will make it very rigid. I did the same thing to match side walls on roof to match lower walls. Once I epoxied glass on upper side walls, I have clamped them to lower walls (with separator PE film of course). So I would to the same with your shell once first glass layer is still green and soft.
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Re: Sleeper for Tacoma

Postby woodslanding » Sat Jun 05, 2021 11:39 pm

yeah, I read a few more threads on the boat builder forum, and some folks just used thin painter's plastic, but others said that stuck and was impossible to get off. So the thicker stuff is probably a good idea. But maybe as you say, it's a case of just waiting longer for it to cure completely....
:thinking:

A plastic place in town has 4X8 .020 thick sheets of "PETG Thermoplastic Sheets (transparent)" for $13. That's a possibility.... .030 goes up to $23. but others preferred cheap vinyl cloth on sale from your local fabric store, and walmart seems to have the stuff dead cheap. https://www.walmart.com/ip/Magic-Cover- ... s/23554847

I suppose I'm going to a lot of trouble just to keep from sanding, but I hate sanding.... and I'm worried my hands are already getting a bit of sensitivity to plastic dust. And though I'm using a mask, I'm sure some is getting in my lungs too.

Next project will be completely CAD drawn in advance, with lots of box joints, and I'll build a maslow CNC machine, and put the foam cutter in there in place of the router, and use different foam thicknesses where needed and do all of this properly, so I'm not creating any dust until after assembly.... I'll also rout plywood frames for all the windows, as seen on these forums... but that will be then and this is now. And if I hadn't tried to do this, I wouldn't know about using a foam cutter instead of a router anyway.

The learning curve continues....

I do have some glass going over plywood, though most of it is foam. Did you not coat the plywood with epoxy first, or did you still have the problem of starvation even after that? I figured I'd coat the plywood with epoxy first, but hoped that wouldn't be necessary with the foam...

Also, complicating things further (I have you to thank for catching this sooner than later) I realized the plywood was sagging in the middle, which the truck bed will not do, so I propped it up, and checked level more carefully. This ended up splaying the walls out about a quarter inch. This means some pieces up higher that I had recut will now be too small and have to be shimmed. All pretty easy fixes, but might have been quite a problem if I waited to put things on the truck until the glass was on. I have the first layer glued now, and when it dries I'm going to set it on the truck to check everything and probably measure and shim the first 45 degree pieces there, so I get the thicknesses right.

Clamping with packing tape seemed to work quite well.... I am still trying to get the right amount of GG on things. Mostly I'm underestimating, which is probably okay, but I'll know more when the tape comes off tomorrow. It just has to stick together until the glass goes on....
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Re: Sleeper for Tacoma

Postby tony.latham » Sun Jun 06, 2021 8:10 am

and I'll build a maslow CNC machine...


I had one for a while. I considered it kind of a Rube Goldberg affair and sold it. I built an MPCNC (mostly printed with a 3D printer) Lowrider 2. You might think about it or V1 Engineering's smaller Primo CNC instead.



The space it sits on was my assembly table. Now it's a dual function table.

Just a thought. :thinking:

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Re: Sleeper for Tacoma

Postby OP827 » Sun Jun 06, 2021 10:09 am

woodslanding wrote:A plastic place in town has 4X8 .020 thick sheets of "PETG Thermoplastic Sheets (transparent)" for $13. That's a possibility.... .030 goes up to $23. but others preferred cheap vinyl cloth on sale from your local fabric store, and walmart seems to have the stuff dead cheap. https://www.walmart.com/ip/Magic-Cover- ... s/23554847

It's funny that I was also looking at these PETG sheets available in my area. I do not know what "G" means (have to ask the supplier) in this material name, but looks like it's a most economical solution out of all plastic sheets. It probably makes sense to leave its protective film on for first trials or use wax to ensure separation. As far as vinyl from walmart of fabric store is concerned, it sure will work, but since it is actually not as flat as more rigid PET film, the resulting surface will have to be more wavy and chasing bubbles could be a bit more complicated. I would say that testing is still required on small scale before attempting the real large surface.
EDIT: "G" must stand for Glycol or "ethylene glycol" as it is one of the Polyethylene terephthalate's chemical reaction precursors.

woodslanding wrote:I suppose I'm going to a lot of trouble just to keep from sanding, but I hate sanding.... and I'm worried my hands are already getting a bit of sensitivity to plastic dust. And though I'm using a mask, I'm sure some is getting in my lungs too.
Me too, so finding a cleaner solution to save time and personal health is well worth it. That is why I am also looking at just using premade skins, but then need to come up with a good solution for covering the sandwich panel seams.

woodslanding wrote:...
I do have some glass going over plywood, though most of it is foam. Did you not coat the plywood with epoxy first, or did you still have the problem of starvation even after that? I figured I'd coat the plywood with epoxy first, but hoped that wouldn't be necessary with the foam...
...
I did NOT coat plywood with epoxy first, it was a "dry on dry" 1x6oz glass layup. I was trying to save time... So going forward it makes sense to wait some time and saturate plywood and glass thoroughly and not to squeeze epoxy away from the laminate too hard. Again, some more experience is needed here. I must say that some plywood pieces came out OK and yes, on the foam I did not really see similar starvation happening. I was using the gift wrap film since then and would still use it to save time (and actually epoxy), but the latest lamination I did for bathroom area roof stiffeners got the gift the thin film stuck pretty good, so I had to sand it off :oops: . That is why I am looking for a thicker PET(Polyethylene terephthalate) film. This method works only on flat or non-compound curve surfaces that can be made of sheet goods, which are foam boards and plywood sheets.
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Re: Sleeper for Tacoma

Postby tony.latham » Sun Jun 06, 2021 1:21 pm

Did you not coat the plywood with epoxy first, or did you still have the problem of starvation even after that?


I have never had a problem with cloth starvation when fiberglassing over wood without applying epoxy prior to the cloth.

Image

Someone once wrote this for a book: ;)

As you wet out the cloth, keep in mind that some of the epoxy will absorb into the wood, which can lead to resin-starved fiberglass. The squeegee is your stethoscope. It will vibrate over starved cloth and glide over areas of excess epoxy. Keep looking at the layup from a low angle for dull or shiny spots. If a spot looks whitish, it needs more resin. Properly saturated cloth is transparent. Adding resin to saturated cloth doesn’t increase the strength.

Pay attention to the edges of the wall and ensure you have good saturation. If you have a raised spot in the fiberglass, work it flat with the squeegee.

When you think you’re done, take a twenty-minute break and then check to make sure that some of the cloth hasn’t lifted or become whitish. You can push lifted spots down with the squeegee. Additional epoxy can be added as long as it’s still tacky.


:thumbsup:

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Re: Sleeper for Tacoma

Postby OP827 » Sun Jun 06, 2021 2:19 pm

Those are very good points Tony, thanks. I think waiting and checking for even surface saturation before applying the PET film would be a key pointer here. I also think that I was just pushing a bit too hard on my squeegee after applying the PET film and that is why glass starvation had happened.
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Re: Sleeper for Tacoma

Postby woodslanding » Mon Jun 07, 2021 12:24 am

tony.latham wrote:
and I'll build a maslow CNC machine...


I had one for a while. I considered it kind of a Rube Goldberg affair and sold it. I built an MPCNC (mostly printed with a 3D printer) Lowrider 2. You might think about it or V1 Engineering's smaller Primo CNC instead.

The space it sits on was my assembly table. Now it's a dual function table.

Just a thought. :thinking:

Tony


Well now, I do have a 3d printer. I'll have a look into this!
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Re: Sleeper for Tacoma

Postby woodslanding » Mon Jun 07, 2021 12:46 am

OP827 wrote:
woodslanding wrote:A plastic place in town has 4X8 .020 thick sheets of "PETG Thermoplastic Sheets (transparent)" for $13. That's a possibility.... .030 goes up to $23. but others preferred cheap vinyl cloth on sale from your local fabric store, and walmart seems to have the stuff dead cheap. https://www.walmart.com/ip/Magic-Cover- ... s/23554847

It's funny that I was also looking at these PETG sheets available in my area. I do not know what "G" means (have to ask the supplier) in this material name, but looks like it's a most economical solution out of all plastic sheets. It probably makes sense to leave its protective film on for first trials or use wax to ensure separation. As far as vinyl from walmart of fabric store is concerned, it sure will work, but since it is actually not as flat as more rigid PET film, the resulting surface will have to be more wavy and chasing bubbles could be a bit more complicated. I would say that testing is still required on small scale before attempting the real large surface.
EDIT: "G" must stand for Glycol or "ethylene glycol" as it is one of the Polyethylene terephthalate's chemical reaction precursors.
woodslanding wrote:...
I do have some glass going over plywood, though most of it is foam. Did you not coat the plywood with epoxy first, or did you still have the problem of starvation even after that? I figured I'd coat the plywood with epoxy first, but hoped that wouldn't be necessary with the foam...
...
I did NOT coat plywood with epoxy first, it was a "dry on dry" 1x6oz glass layup. I was trying to save time... So going forward it makes sense to wait some time and saturate plywood and glass thoroughly and not to squeeze epoxy away from the laminate too hard. Again, some more experience is needed here. I must say that some plywood pieces came out OK and yes, on the foam I did not really see similar starvation happening. I was using the gift wrap film since then and would still use it to save time (and actually epoxy), but the latest lamination I did for bathroom area roof stiffeners got the gift the thin film stuck pretty good, so I had to sand it off :oops: . That is why I am looking for a thicker PET(Polyethylene terephthalate) film. This method works only on flat or non-compound curve surfaces that can be made of sheet goods, which are foam boards and plywood sheets.


I don't know what the G stands for, but PETG is what I use in my 3d printer...

I wish I knew why the film sticks sometimes and not others.
I'm not sure with the angles I have I'll be able to fit the thicker plastic to everything. Not sure how flexible the .020 would be.
I wonder if you can re-use it?
I did read that chasing bubbles was harder with the vinyl, so you are right about that.

Tony, so you would not recommend putting a layer of epoxy on my plywood first? Or just that it's not a disaster if you don't? Always glad to cross one step off the list. And do you have anything to weigh in on about plastic film?

One thing I'm not clear of here. I have heard you should do several coats of resin after the first saturating one. I assume the plastic is for over the first (saturating) coat, not the last one? Or are multiple coats even recommended in this application?

In other news, the gluing went well, but I'm glad I erred on the side of less glue. Everything is plenty sturdy, even when the glue is only contacting in a few places because of wobbly cuts. The one mishap was where glue pushed a panel slightly out of line from expansion, despite the tape. Seems I needed a little less glue or a little more tape. I will probably cut the seam and redo it. It was on the edge of the back door, so the tape had less of a purchase.
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Re: Sleeper for Tacoma

Postby tony.latham » Mon Jun 07, 2021 7:50 am

Tony, so you would not recommend putting a layer of epoxy on my plywood first?


You can do it either way. I don't find it necessary to apply a layer first. If you do it, just make sure to add the glass/epoxy on top of it before the first layer is cured.

I have heard you should do several coats of resin after the first saturating one. I assume the plastic is for over the first (saturating) coat, not the last one? Or are multiple coats even recommended in this application?


I'm scratching my head on where you might have heard that. The only reason to add more epoxy is to fill the weave for appearance's sake.

What is your final finish? Are you painting or clear coating? The best stuff to fill the weave with is a peanut-butter like slurry made from epoxy/microspheres. It sands easily. The downside is that it is white.

With your angular design, I think applying a pseudo-plastic peel ply might turn into a rodeo. If you overlap the stuff and get epoxy in between the layers, it could create more finish work for you. Just a thought.

I read that you are using both glass and carbon cloths. What are your layup and cloth weights?

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Re: Sleeper for Tacoma

Postby woodslanding » Mon Jun 07, 2021 10:50 am

So you would expect to fill with one coat. I like that... I'll go with it. I think the boat builders do several coats? I got non-blushing resin, thinking of multiple coats, but maybe that was unnecessary.

I like the idea of not putting resin on first, so it's easier to get the cloth to lay flat. But in any case, glassing the wood will probably be a separate step. I'll want to do the layup on the top first, then turn it over to do the plywood bottom, and finally do the interior. Unless there is a reason to do the inside first. I suppose the advantage to doing the inside first is that you get some practice there where it's less visible. Problem is, to do the ceiling I was figuring to turn it on its back, which I wouldn't want to do until it's got some structure. Trying to avoid doing layup over my head.

I suppose I could put it on its side to do the interior, if I wanted to do that first. Then the ceiling turns into a wall. And the foam doesn't have to take the full weight of the plywood. One of the walls will turn into a ceiling that way, but I suppose I could rotate it as I go. The interior, being concave, seems like it might be harder to layup.

My original thought with plastic was something thin and stretchy, which some folks have had good luck using. That was over wood. The edges on my foam will all get rounded off, if that is a factor... I am leaning now towards just trying to get a fairly smooth coat by hand. I do have microballoons and silica, which I will fill gaps with before the glassing, but maybe more after will be helpful. I guess I need to make sure not to let that cure fully before putting on the glass? I've also read of folks priming and then sanding it off, to find low points. I don't remember what they filled with after that.

I read that if you used a slurry for the layup, you wouldn't get good penetration of the cloth. I got Raka, because I heard that being thinner, it was good for hand layup. So maybe put the thin resin on first, and then fill with slurry where needed for low spots?

The epoxy I have is Raka 127 Thin Resin with 350 Non-Blushing Hardener.

I'm totally planning to paint. The foam is not a thing of beauty! I've heard deck paint is a good choice, there is also bedliner, which would offer the best protection. And maybe hide some imperfections!

My fiberglass is 7.5 oz, and the carbon fiber is 5 oz. I think just FG would have been fine, but I want to try using some CF also, just to get the feel of it. And it was surprisingly reasonable in price. This is mostly just a big experiment. I do hope it's reasonably sturdy, but if it doesn't look super pro, I can live with it. If it's not sturdy enough, I could always put another layer on, I suppose. And I will know whether I just want to go with some kind of panel construction next time!
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Re: Sleeper for Tacoma

Postby OP827 » Mon Jun 07, 2021 5:59 pm

So you would expect to fill with one coat. I like that... I'll go with it. I think the boat builders do several coats? I got non-blushing resin, thinking of multiple coats, but maybe that was unnecessary.
- I am not a boatbuilder, but I read that they historically/normally go with several coats and then fairing for moldless lamination, especially on compound curve surface. A single epoxy application is my ultimate goal and I have now proven it to work on small surfaces with the film and there will be no blushing with any kind of epoxy as there is no air contact with epoxy surface.

I like the idea of not putting resin on first, so it's easier to get the cloth to lay flat. But in any case, glassing the wood will probably be a separate step. I'll want to do the layup on the top first, then turn it over to do the plywood bottom, and finally do the interior. Unless there is a reason to do the inside first. I suppose the advantage to doing the inside first is that you get some practice there where it's less visible. Problem is, to do the ceiling I was figuring to turn it on its back, which I wouldn't want to do until it's got some structure. Trying to avoid doing layup over my head.

I suppose I could put it on its side to do the interior, if I wanted to do that first. Then the ceiling turns into a wall. And the foam doesn't have to take the full weight of the plywood. One of the walls will turn into a ceiling that way, but I suppose I could rotate it as I go. The interior, being concave, seems like it might be harder to layup.
- I would try to make gravity to stay on my side whenever possible for epoxy laminations.

My original thought with plastic was something thin and stretchy, which some folks have had good luck using. That was over wood. The edges on my foam will all get rounded off, if that is a factor... I am leaning now towards just trying to get a fairly smooth coat by hand. I do have microballoons and silica, which I will fill gaps with before the glassing, but maybe more after will be helpful. I guess I need to make sure not to let that cure fully before putting on the glass? I've also read of folks priming and then sanding it off, to find low points. I don't remember what they filled with after that.
- You could fair/fill seams and corners and use microballoons or GS foam for that. Then sand the foam flat panels flat with a good homemade long board once the panels are glued together. It should not take much effort, foam is soft. Then finish making nice corners. Then laminate FG and apply flat pieces of film per each flat panel size and cover rounded corners by a small FG overlap (not to reach other flat surface) for future sanding/fairing, which will be much less. You could cut excess FG after the epoxy gelled right on the foam panel since the cut will be filled with epoxy and covered by other adjacent FG panel. IMHO, thin and stretchy plastic is not likely to work great, it most likely will create wrinkles that are hard to smooth, FG would want to move with it and create issues. Please test it and report here for everyone's benefit if you go that route.

I read that if you used a slurry for the layup, you wouldn't get good penetration of the cloth. I got Raka, because I heard that being thinner, it was good for hand layup. So maybe put the thin resin on first, and then fill with slurry where needed for low spots?

The epoxy I have is Raka 127 Thin Resin with 350 Non-Blushing Hardener.
- Slurry is usually put on surface before FG. You could apply slurry to a sanded foam then lay FG and add plain epoxy on top to fully saturate FG. That is how Rutan's moldless composite aircraft wings were built.

I'm totally planning to paint. The foam is not a thing of beauty! I've heard deck paint is a good choice, there is also bedliner, which would offer the best protection. And maybe hide some imperfections!

My fiberglass is 7.5 oz, and the carbon fiber is 5 oz. I think just FG would have been fine, but I want to try using some CF also, just to get the feel of it. And it was surprisingly reasonable in price. This is mostly just a big experiment. I do hope it's reasonably sturdy, but if it doesn't look super pro, I can live with it. If it's not sturdy enough, I could always put another layer on, I suppose. And I will know whether I just want to go with some kind of panel construction next time!
- It is a personal choice and budget consideration as to how to protect and finish the surface. FG alone provides good strength. CF is much more rigid (similar to carbon steel Young Modulus) but more brittle than FG when it comes to impact resistance and CF can break into very sharp shards, that is why CF is often combined with Kevlar on top of it to reduce the risks. I used a very little CF in places where I wanted more rigidity like the fins for weather stripping of the sides. I personally prefer 2 stage automotive polyurethane paint and clear coat for gloss finish and Monstaliner for textured finish due to their higher resistance to wear, weather and UV damage.

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Re: Sleeper for Tacoma

Postby tony.latham » Tue Jun 08, 2021 7:21 am

I guess I need to make sure not to let that cure fully before putting on the glass?


Yes, you'll end up with a single layer of epoxy instead of one bonding to a second.

I read that if you used a slurry for the layup, you wouldn't get good penetration of the cloth. I got Raka, because I heard that being thinner, it was good for hand layup. So maybe put the thin resin on first, and then fill with slurry where needed for low spots?


You do not want to add a thickening agent to the resin used to laminate. After the laminate is nearly cured, then add a thickened layer to fill the weave if needed.

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Re: Sleeper for Tacoma

Postby woodslanding » Fri Jun 11, 2021 10:00 am

Wow, thank you, that is a wealth of practical suggestions!

Yeah, I guess if you were using mylar, that is not at all stretchy. I did see someone use a stretchy plastic for a repair on a kayak, and that's what gave me the idea initially. But scaling that up?? Yeah, maybe not so good.... It seems like the boat people tend to put on a thinner first coat, not attempting to fully fill the weave, and let it set up somewhat, and then do a fill coat (or even two) to finish. That would keep the FG from moving around. I did use some plastic wrap on my keyboard project, but I don't remember the extent. Never enough pics! Here's one from that phase of construction. Looking now, I can see that I didn't completely fill the weave in spots....

Image

The filling and sanding before layup you described is pretty much exactly what I planned. But using the thicker plastic cut to size... that's a very interesting idea. I'll think about that for sure. Then yeah you just have to sand the edges between. But I may just do straight layup and deal with the results afterwards. I kind of feel like I'll have my hands full just doing that, since this is my first significant project!

I read that CF is actually more impact resistant than kevlar, although less abrasion resistant... (but I'm not so sure that's correct--you can read anything on the internet!) so that was my thinking for using it on the roof. I do know about it splintering, and I suppose where hail would dent a FG roof, large enough hail might splinter a CF roof.... maybe this will be the test case for that.
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