tag:blogger.com,1999:blog-4773370276862539169.post3607389998000038086..comments2024-03-24T03:23:46.858-06:00Comments on This Rat Sailed: Fiberglassing in the DarkMike Boydhttp://www.blogger.com/profile/14279932231094933575noreply@blogger.comBlogger10125tag:blogger.com,1999:blog-4773370276862539169.post-24702037439726268832015-08-19T09:05:43.869-06:002015-08-19T09:05:43.869-06:00Hey Dave,
Thanks for the info. Nice to know the ...Hey Dave,<br /><br />Thanks for the info. Nice to know the cheaper substitutions for some of the expensive vacuum bagging stuff. I wish I could vacuum bag the top, but I just can't see how to do it with my current setup. Right now I'm just trying to keep it from raining on what I have done. Working out in a boatyard is far from the ideal anyway.<br /><br />And yes, I'm a bit jealous. Would much rather be having some fun than doing this...but this is a step toward that goal anyway.<br /><br />Did you ever find a light for your instrument cluster? Seems like a LED would be better than any sort of incandescent bulb.<br /><br />-MikeMike Boydhttps://www.blogger.com/profile/14279932231094933575noreply@blogger.comtag:blogger.com,1999:blog-4773370276862539169.post-28109428756894536592015-08-19T06:52:43.360-06:002015-08-19T06:52:43.360-06:00Hi Mike -
Been out sailing. Envious? :-)
With a va...Hi Mike -<br />Been out sailing. Envious? :-)<br />With a vac bag, you get all your tacky tape in place around the perimeter, leaving the tape upper surface papered on three sides. The fourth side will already have the plastic sheet stuck to it, with the sheet folded away from the part you are building. You can catalyze at the low end 1-1/4% or so or use a BPO activated putty that has more leeway for adjusting catalyst times. It helps to do a test sample off to the side to be sure of time. Yes, once you put the matrix down, you need to move fast (that's what's so nice about epoxy and longer pot life). I have also refrigerated the matrix to get a cool start on it.<br />For the vac penetration, cut a hole barely large enough for the vac hose fitting, stick the hose in, and seal with tacky tape all around.<br />As far as something to spread the vacuum, bubble wrap under the plastic works great (keeping it in from the edges a bit), or you can take poly tube, drill holes in it and snake it back and forth on the core surface, holding in place with tape or tacky tape. The vac has to be located over the tubing in order to work.<br />The peel ply makes it easy to remove everything and leaves a fairly nice surface, but it is not necessary. The plastic stuff will all peel away and the surface might be a bit lumpy, but as you found out, it needs to be sanded smooth anyhow.<br />The cure will not be inhibited under the bag, The process increases the odds of getting a uniformly wetted laminate. Some cores will off-gas (don't believe those who say Divinycel does - it's usually process caused in this case) and some cores, with a slow gel time resin, will react negatively to high styrene levels. It's always good to test your process and chemicals if treading into unknown waters. <br />I would imagine there are a bazillion videos on-line showing everything from basic to advanced.<br />Looking forward to seeing your completed product.<br />Dave<br />https://svfifthquarter.wordpress.com/Davehttps://svfifthquarter.wordpress.com/noreply@blogger.comtag:blogger.com,1999:blog-4773370276862539169.post-68899637056258935812015-08-14T16:44:04.357-06:002015-08-14T16:44:04.357-06:00Thanks guys. I did find a roller that I think wil...Thanks guys. I did find a roller that I think will work when using thickened gel coat. Picture of my various trials posted on my Facebook page: <a href="https://www.facebook.com/ThisRatSailed" rel="nofollow">https://www.facebook.com/ThisRatSailed</a>Mike Boydhttps://www.blogger.com/profile/14279932231094933575noreply@blogger.comtag:blogger.com,1999:blog-4773370276862539169.post-35204822476839154292015-08-14T15:21:55.110-06:002015-08-14T15:21:55.110-06:00Mike, you can purchase a "texturing roller&qu...Mike, you can purchase a "texturing roller" from Jamestown. It is used to apply a non-skid coating called Kiwi Grip (I think). I have used it on wing walk on airplanes with good success. Tim & Kathy Goddardhttps://www.blogger.com/profile/09919620866225444319noreply@blogger.comtag:blogger.com,1999:blog-4773370276862539169.post-78085980460244420632015-08-13T20:23:31.970-06:002015-08-13T20:23:31.970-06:00Hey Dave, I'd love to try vacuum bagging but I...Hey Dave, I'd love to try vacuum bagging but I just don't see how to do it given my setup. I don't have any perimeter outside the layup where I could seal anything. I've got several flat sheets of 1" foam and a curved set of stringers that I need to bend the foam over. Since it isn't a solid mold (and I have no real way I can think of to make a curved table that I could seal against here) and best option I seem to have is to tie the foam to the curved stringers, I just don't know how I can keep a vacuum that wouldn't draw in air and suck out the resin.<br /><br />A couple general questions for you though. If you are doing a large part and vacuum bagging it, how do you get everything assembled before the polyester starts to cure? In the temperatures here, I just can't see getting a mix that will last long enough to get everything laid up and bagged before it cured. And for the shop vac approach, how do you attach it to the bag without the usual fittings? And to get the vacuum, don't you need other material in between the part and the plastic that allows the vacuum to pull out all the air? I thought the procedure was to use peel ply and some sort of media/fabric that will allow the pump to suck the air out? And if the bag is used, then won't the laminating resin fully cure?<br /><br />Even if I can't do it this time, curious to know how your low-tech process would work.Mike Boydhttps://www.blogger.com/profile/14279932231094933575noreply@blogger.comtag:blogger.com,1999:blog-4773370276862539169.post-16016250458334153132015-08-13T19:24:33.508-06:002015-08-13T19:24:33.508-06:00Do your first layup down hand. Do you have enough ...Do your first layup down hand. Do you have enough perimeter to add some butyl tacky tape? You need at least a couple inches - it really is not that difficult. Plastic sheet from Lowes/Home Depot works fine, you aren't doing aerospace. And a shop vac. You may not have noticed a difference but down the road, if any water, more air, laminate separation starts to happen, well, you could get a massive separation of the sandwich panel.<br />Go to youtube - there are a million examples. Just sayin'Davehttps://svfifthquarter.wordpress.com/noreply@blogger.comtag:blogger.com,1999:blog-4773370276862539169.post-78163763234947980252015-08-13T07:19:00.316-06:002015-08-13T07:19:00.316-06:00In my test panel I only did half of it with the ho...In my test panel I only did half of it with the holes. Honestly, I didn't notice any difference in the panel. I've even jumped up and down on it while it was suspended by the very edge of a couple of wood blocks (about 1" x 4" lip). So, I think the hand layup will work fine. Having said all of that, sanding the nibs off the back wasn't that bad...came off with 60 grit pretty quickly. The idea of them releasing any trapped air seems to me to be the bigger possible advantage if there is any air trapped under the thick mat.n The bigger pain is pressing, and then removing, the board full of nails. Even my 1 foot by 2 foot nail board is difficult to pry off the foam once it is pressed into it. Mike Boydhttps://www.blogger.com/profile/14279932231094933575noreply@blogger.comtag:blogger.com,1999:blog-4773370276862539169.post-82422688564980751972015-08-13T06:59:42.989-06:002015-08-13T06:59:42.989-06:00Hi Mike,
Would a 1/4" -1/3" deep larger ...Hi Mike,<br />Would a 1/4" -1/3" deep larger dia nail hole, a dimple or shallow 1/4"-1/3" V (none going all the way through) into the top and bottom of the foam increase the surface area and mechancial bond of the resin to the foam be a substitute to nail holes all the way thru and having to sand hundreds of drip thru's? Would need to be shape that allows flowing of resin into hole without a bubble on top- assumes you put resin on and do layup while mold/foam is nearly horizontal.<br />Shop vac is a possibility if you have, small Vacuum pumps run around $100 at your favorite Harbor Freight ( but I doubt you would have a future use for), but then you need the sheet plastic, tape/hoses etc<br />Mostly it's a matter of building a strong enough bimini for your needs, and it would be easier if you don't have to vac-bag.<br />Doug from VTAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-4773370276862539169.post-13189769547261991902015-08-12T19:10:15.530-06:002015-08-12T19:10:15.530-06:00Hi Dave. Well, I guess it would have the same eff...Hi Dave. Well, I guess it would have the same effect on the first hand layup on one side (providing you can squeeze the bubbles over to the holes). So, in my case, doing hand layup, is it worth the effort to poke all those holes (it is a time consuming PITA)?Mike Boydhttps://www.blogger.com/profile/14279932231094933575noreply@blogger.comtag:blogger.com,1999:blog-4773370276862539169.post-24365691291070008882015-08-12T18:27:07.908-06:002015-08-12T18:27:07.908-06:00Mike - the purpose for the regularly patterned hol...Mike - the purpose for the regularly patterned holes is so that when you press/weight/vacuum bag the core into its catalyzed substrate, the air beneath the core will get pushed/pulled out the holes so you don't get big air voids beneath the core. I used to work for DIAB as an engineer. You'd be surprised how well the vacuum on an older pickup truck works to hold a vacuum bag when the power goes out. Or, how well a shop vac works in the backwoods of Alabama when showing a crew in a shop with a dirt floor how to bag large panels. Oh, the stories .....<br />Dave<br />https://svfifthquarter.wordpress.com/Davehttps://svfifthquarter.wordpress.com/noreply@blogger.com