Hello I am new to the forum as a poster, but I have been reading the posts for some time now. I am sure that this is posted somewhere on the forum but I can not find it. Here is my problem. I have been building SUPs and Logs since the begining of the year and I am getting pin bubbles all over in my laminate. Now they are are not the tiny air bubbles you get when you may leave too much resin pooled in one area and they rise. But instead they are many pin type bubbles that are inbetween each weave pattern so the tiny air bubbles are uniform in pattern. Am i pulling too much resin out? I have looked all over the web to remedy this and I get a bunch of mixed results. Am I using crappy product? I get all of my E glass from Surf source (I am in FL) But I use quality resin (Green Room). I usually get the majority of these bubbles around the cut/free lap area and the tail, but I have seen them on both the deck and bottom as well. Now I have been sanding the entire lam coat before hot coating. Could this be a problem? I do clean out the weave rather well after sanding it prior to the hot coat. Am I not sealing the eps well enough? (I use Fast and Final DAP). As you can see I am frustrated with this and I could ask all kinds of questions as to what I may be doing wrong. But I wonder if anyone has seen this or had this problem. I have tried the foam roller technique to make sure the lap is saturated well enough but still see the pin bubbles
Are you being careful to do the lamination when the temperature is falling? It possibly is out gassing from the core.
Also if you are doing a nice hand lamination with the glass texture still showing then sanding the laminate before fill coating is not a good idea. You’d only be sanding into the glass.
Your condition is air bubbles trapped in the criss/cross weave pattern, aka ‘‘pin air.’’ It’s generated by a little too much pressure on your resin pull. Actually a difficult condition to do on purpose. The tiny air bubbles, if uniformly throughout the weave, actually make it stronger, and lighter. This according to General Dynamics engineers, who required the ‘‘condition’’ throughout the layups on missle nose cones. The tiny spheres in the resin matrix have a high resistance to compression load. Several light pulls, to remove resin, might serve you better. You’ll quickly learn not to do that ‘‘one more pass’’, that produces the pin air condition. Practice, practice, practice.
check out wood ogre’s technigue using sponge rollers and brushes
Thanks for the reply thrailkill. What you say makes sense because I am a little overzelous when it comes to pulling out the resin so I have got pin air in every one of my boards lately. I always hit up the lam one more time once I have tucked the rails which I think I will try passing on with the next board build. I have always read that you don’t want too much shiny resin visible or pooling of resin so I try to get it all out which is obviously my problem. I don’t mind the pin air in my own boards but potential friend or customer boards is not always desirable. I do both foam painting and resin tint and it is more predominate in the foam paint.
I actually have a controlled climate shop because our Florida temps have already been 90+ with super humidity all ready this year.
What kind of squeegee are you using? A lot of Epoxy guys like to use those little yellow hard plastic ones. They work great for pulling excess resin off. Sometimes, too much gets pulled. One edge is really sharp the other soft. The soft side leaves a little more resin. Maybe a little less pressure.
Maybe your resin is really warm and thin. This happens in warm climates.
Thalco makes nice soft rubber squeegees too.
Good luck.
I use both a 8" Thalco and the yellow auto body type. But mainly the Thalco. I’ll admit at first that I used the thalco straight out the box before it was pre softened thinking that was my problem. Then I talked with a friend in my area that ran QC at Pearson Arrow surfboards in Santa Cruz and he showed me how to round the corners and dull up the sharp edge. I really only use the yellow squeegees on cleaning up the rails as seen in the JC glassing 101 video;) This may sound stupid but I used to live a bodybuilder lifestyle and I just recently eased up on the weights, but maybe when I pull resin I am pulling way too much because I have a much heavier touch than most.
Wow Bill, That’s interesting.
I’m doing a board right now, where I have micro pin holes everywhere. I used warp cloth on a wet out table, and into a vacuum bag. It wetted out perfect on the table, but when transfered to the board, the laminate was so lean, that while the glass was saturated, the voids between the fibers are empty. Made it look sort of frosty. So you are saying it is actually stronger?
It wouldn’t have been too noticable, but the bottom layer of cloth was red.
Mark,
The voids between the fiber strands must be occupied by a spherical bubble. The resistance to compression load is similar to the crush resistance of an egg, when load is applied end to end. Fresh out of high school I worked in the plastics department at Convair/General Dynamics.
Newleaf,
With epoxy don't use the thalco, use the bondo spreader. 1) get all the material out on the board, spread it around and let saturate. don't rush, wet out the rail drape, let it sit....you have time. 2) With epoxy you want to work in a small area, don't walk the board like poly. The more you pull the epoxy around the more you froth and bubble it up. 3) So now you have the board wetted out, and semi laminated down( meaning you have all the air pockets and wobbles out, but not firmed down to the foam....3) now the epoxy is getting into its sticky stage (something like 18.546 -28.554 min into the process). This is the time you laminate glass/epoxy/foam into one substrate. Pull just enough epoxy off so the top of the weave is showing..but not wringed out dry. Thing of a sponge: if you leave a sponge too wet it will drip all over the place. if you wring out a wet sponge too much it will want to suck in air. What you want is a wet sponge that doesn't drip.
As Bill said..practice.
In my opinion the yellow bondo spreaders are too stiff and rake over the glass… we use the brown resin spreaders, they have a real nice subtle flex for lamming with epoxy.
~Brian
right you are. I use the redish brown ones from 3M. I call them Bondo spreaders in the generic sense.
Lots of epoxy/styro builders use a spackle coat process after the lamination coat, sometimes even if the board is vacuum bagged. A slurry mix of microballons/epoxy resin, viscous close to 90 weight oil, is squeegeed repeatedly over the lam coat, to fill the micro air bubbles.
UPDATE Thanks Resinhead.
I did this verbatim on a recent 11" SUP and it worked great!! I did indeed use the brownish?Bondo spreaders instead of both the Thalco and yellow autobody spreader. I was watching most of the “glassing surfboards videos” via youtube and JC’s Glassing 101 but it was mostly polyester. So I did indeed work epoxy like polyester (Fast and walked the length of the board) I did not let the epoxy sit and soak up into the glass. The only place I see pin air (very little) now is by the hard edge of the tail, which I came to expect that though. Thanks again.
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Newleaf,
With epoxy don't use the thalco, use the bondo spreader. 1) get all the material out on the board, spread it around and let saturate. don't rush, wet out the rail drape, let it sit....you have time. 2) With epoxy you want to work in a small area, don't walk the board like poly. The more you pull the epoxy around the more you froth and bubble it up. 3) So now you have the board wetted out, and semi laminated down( meaning you have all the air pockets and wobbles out, but not firmed down to the foam....3) now the epoxy is getting into its sticky stage (something like 18.546 -28.554 min into the process). This is the time you laminate glass/epoxy/foam into one substrate. Pull just enough epoxy off so the top of the weave is showing..but not wringed out dry. Thing of a sponge: if you leave a sponge too wet it will drip all over the place. if you wring out a wet sponge too much it will want to suck in air. What you want is a wet sponge that doesn't drip.
As Bill said..practice.
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UPDATE Thanks Resinhead.
I did this verbatim on a recent 11" SUP and it worked great!! I did indeed use the brownish?Bondo spreaders instead of both the Thalco and yellow autobody spreader. I was watching most of the "glassing surfboards videos" via youtube and JC's Glassing 101 but it was mostly polyester. So I did indeed work epoxy like polyester (Fast and walked the length of the board) I did not let the epoxy sit and soak up into the glass. The only place I see pin air (very little) now is by the hard edge of the tail, which I came to expect that though. Thanks again.
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No problem. I'm glad it came out better this time.
It's really easier than poly, cause you don't have to rush. The trick on the tail and nose wraps is to let the epoxy set up a bit, let it get sticky. Letting it get really tacky will help the cloth defy gravity and stay put where it should.
I keep about a spoon full of clear unfrothed epoxy left over in a small cup. The last thing I do before I walk away from the board is put a dab of very sticky goop on the nose and corners. The uber sticky epoxy will stay put and not run off and under the board, This allows any pull away from the cloth to be filled with clear epoxy goop. It a lot easier to sand down the giant zit, than to dig out a bubble and repair. Any small pins or bubbles will be fixed with the hot coat.