Devlin bluebill build thread.
- Thread starter Paul W
- Start date
The biggie for me is rather than delam, when the glass floats it rises up on pools of resin (you have seen this) and the glass is wavy or has hills and thus the surface of the glass isn't flat. So how can you deal with that?. If you sand you will take the tops off the hills, which will leave holes in your glass. You can cover them and fair, but that is a lot of work adn extra weight if you care about the finish. It is clear that you have some really clean work in there as well, so you know what you are doing.
I am in the process of sanding all my epoxy filled joints on the outside, and really making sure the scarfs and everything are nice and smooth right now.
Does anyone have any tips for the sheathing process for the outside? I will be taking this adventure on this coming Saturday. Any advice or tips would be much appreciated. I do have someone who says he will mix epoxy batches while I spread or roll them out.
Does anyone have any tips for the sheathing process for the outside? I will be taking this adventure on this coming Saturday. Any advice or tips would be much appreciated. I do have someone who says he will mix epoxy batches while I spread or roll them out.
It is one of the easiest steps there is. People find it intimidating, but it is easy. Lay the 'glass on the hull and cut roughly to shape. Use a little tape if if wants to slip off (you won't need it once you get a little epoxy on there. All I use is a resin cup and a yellow autobody squeegee - some people use rollers, but I've never needed them. Pour resin ny the pint on the glass, startign in the center and work outward. Use the squeegee to push away from the wetted glass. The glass should wet out quickly and you just have to spread the epoxy around. There may be a couple places where the glass won't take the angles (transom, bow), just cut and pleat.
This is one of those steps where you want to remove all the excess epoxy from the cloth so it doesn't float up. You can wet out and get your cloth on where it goes and then do a final run over where you strip all the excess off, that gives the whole thing a while to sit and the wood can absorb some epoxy and everything isn't starved. Then you strip the excess. The whole process should not take too that long. The weave should show strongly at this step.
After the epoxy is tacky or set up, but before too long goes by (overnight is fine) fill the weave. You don't want the epoxy to cure fully. Full cure actually takes several days or weeks, and there is debate when you can still get a chemical bond between the original expoxy and weave filler, but if you do it before the original expoxy is not fully hard, you are sure of a good chemical bond. The longer you wait the more likely you will have a swarm of bugs or pollen end up on the hull. I do this the same way, pour epoxy from cup and squeegee. If you start in the morning you can fill the weave before the evening or just do it the next morning.
Pete McMiller
Well-known member
Tod described the process but I prefer the rollers. Certainly have squeegees handy but do yourself a favor and try both. I help out a local strip boat builder several times a year when it's time to sheath and he uses rollers 95% of the time. Once I tried it, I did also.
For a third opinion on glassing (surely there are more coming!) I use a squeegee for most of the initial epoxy coat over glass. One nice thing about the squeegee is that it's hard, so you can use to push the glass fabric around a bit. This is helpful when trying to get the glass to conform around fillets, corners, etc.It also helps in getting the glass to conform to rounded or curved surfaces, where you can use the squeegee to help stretch the glass and remove any wrinkles.
Finally, the squeegee helps you work excess epoxy out to the edge of the cloth, and you can even pick it up and put it back in your pot or move to a fresh part of the cloth.
But for large simple flat surfaces, and especially for the second coat of epoxy to fill the weave, the rollers are faster and neater.
Do not use staples hold the glass to the hull and epoxy over them! This may sound obvious, but someone did that to the glass on a boat I restored, and when I started my project I found at least one on-line source that recommended that. On the boat I restored that had been stapled, the staples didn't help get a good glassing job, but they sure made it hard to strip the old glass. I ended up with lots of torn out divots in what was otherwise a beautiful cedar strip hull.
Finally, the squeegee helps you work excess epoxy out to the edge of the cloth, and you can even pick it up and put it back in your pot or move to a fresh part of the cloth.
But for large simple flat surfaces, and especially for the second coat of epoxy to fill the weave, the rollers are faster and neater.
Do not use staples hold the glass to the hull and epoxy over them! This may sound obvious, but someone did that to the glass on a boat I restored, and when I started my project I found at least one on-line source that recommended that. On the boat I restored that had been stapled, the staples didn't help get a good glassing job, but they sure made it hard to strip the old glass. I ended up with lots of torn out divots in what was otherwise a beautiful cedar strip hull.
Yes on the staples or anything that fixes it on the hull. The glass when wetted is more flexible and can stretch some or change shape as pushed along with the squeegee, so what you have is not exactly what you will get.
Good fun, I wish I was doing some glassing not joint compound.
If you start in the morning, DO NOT pull it outside into the sun until the epoxy is fully set up. Always epoxy and 'glass under constant or falling temps uenless you like millions of bubbles infusing your epoxy as the air in the wood expands. This doesn't become a huge deal until you have a lot fo encapsulation (as in high percentage), but if you have a problem, it can really be a mess.
T
And don't epoxy late in the evening in your open barn and then leave on the barn light when you go to bed unless you really like sanding insects.
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Ray
Well-known member
Another user of auto body squeegy first then a roller second. Or keep using the squeegy if you like it. Depending on hardner type the rollers can end up going off during a hull covering, which can be exciting if its warm enough. Nothing like smoking epoxy "pop rocks" in your hand. If you go with the roller make sure you have a second one set aside for when (if) the epoxy starts to set up in the foam.
Some folks like to coat the wood then place the glass to make sure the wood does not starve the glass. Unless you have several helpers to lay the glass out this method can result in very messed up glass layout. If you work in small batches, methodical wetting out the glass on a dry hull works just fine.
How are you mixing your epoxy? I recommend using a drill powered stirrer. I use a section of broken arrow saft with a short section of wood dowl in each end. Have to use a masking tape gasket to keep it wedged in there. In one end I have two opposing sheet rock screws that act as paddles. I use an old cheap corded drill set to a low speed to mix the epoxy. It keeps your hand from wearing out over the course of the layup process. It also keeps the mix quality really high and consistant.
Some folks like to coat the wood then place the glass to make sure the wood does not starve the glass. Unless you have several helpers to lay the glass out this method can result in very messed up glass layout. If you work in small batches, methodical wetting out the glass on a dry hull works just fine.
How are you mixing your epoxy? I recommend using a drill powered stirrer. I use a section of broken arrow saft with a short section of wood dowl in each end. Have to use a masking tape gasket to keep it wedged in there. In one end I have two opposing sheet rock screws that act as paddles. I use an old cheap corded drill set to a low speed to mix the epoxy. It keeps your hand from wearing out over the course of the layup process. It also keeps the mix quality really high and consistant.
Steve Sanford
Well-known member
Tod~
Great explanation!
Question: Do you ever add anything - e.g., Cabosil? - during the weave-filling step, so it isn't as likely to run out, especially on vertical surfaces?
(Related bonus question: Can you usually fill the weave with a single coat?)
All the best,
SJS
Great explanation!
Question: Do you ever add anything - e.g., Cabosil? - during the weave-filling step, so it isn't as likely to run out, especially on vertical surfaces?
(Related bonus question: Can you usually fill the weave with a single coat?)
All the best,
SJS
You know, I thought about using microballons in the epoxy to fill the weave, and tried putting some in, but didn't like the result in liquid form. Obvously you could make up some fairing compound and apply the thickened mixture with a knife.
I've always been able to fill the weave with one coat, but I haven't used the really heavy cloths.
Cody Williams
Well-known member
There is probably a "magic mixture" of filler to epoxy for filling the weave, but I've never been able to get it right. I've tried a few times to do my filler coat with cabosil or microballoons in the resin but getting the right ratio of spreadability is really hard to do IMO. If you're using 6oz glass then straight epoxy will fill it no problem. When I built surfboards the filler coat was called the hotcoat because it was set up to kick off pretty quickly, filling the weave before the resin could get drippy and cause extra sanding.
If I recall in Devlin's book he talks about using a cabosil-thickened epoxy coat as the final sanding coat on the hull, again I've tried this but never been able to really make it work. Has anybody else gotten good results using that formula?
If I recall in Devlin's book he talks about using a cabosil-thickened epoxy coat as the final sanding coat on the hull, again I've tried this but never been able to really make it work. Has anybody else gotten good results using that formula?
Here's the hull sheathed before filling the weave. I think i have the weave pretty well filled now, only took one coat, but i probably put it on too thick or something. will be sanding it later this week, then adding keels and painting it. (hopefully) then I will be flipping it over and finishing it on it's trailer that I am fixing up currently. took it all apart and rolled some paint on it yesterday, will be doing tires and wheel bearings soon.
Looking good! Have fun sanding--and wear a good mask. Epoxy dust is nasty stuff and some folks react to it.