Ok got a couple questions. I ran into some little brain scratchers today while glassing and sanding and was hoping for some help.
Is it recommended to make slits in your lap when you just lay down your cloth before glassing? My point being that I believe there is less of a chance that the glass will scrunch up when you glass your laps over. However some people are saying it weakens the cloth bond.
What are some tips on how to cut out the glass for the nose.
3)** When doing your hotcoat, is it good to tape the edges off on both the deck and bottom hotcoat process? That way you can avoid the drips that run off the bottom of the board when doing both sides. I was wondering if there was anything against that.
Sanding I believe is my weakest area. If anybody can shed some light on this topic for me that would be great. Any general tips on it would be great.
Tons of info in the archives on these topics, so spend some time doing some reading and you’ll learn a lot. Here’s some quick direction…
If the slits you refer to are “relief cuts” they’re not necessary along most curves. Only really tight curves and corners. Search “relief cuts.”
Others do it differently, but I do a tab and two v-notches. Looks kinda like this… |/|_|| Lap one point under, then the tab, then the other point. Don’t mess with it, just get them down tight and walk away.
I tape off both sides, right along the same line. No overlap, no gaps. Lay the tape right ON the line at the apex. Search “hotcoating”
Low rpms for the lower grits, higher rpms for the higher grits. Use the proper adhesive to save your pad. Stay off the rails with the grinder… do these by hand with the used disk once your done your flats until you know what you’re doing. I’m no pro, but I like the hard pad for the first couple grits, medium for the next few, soft for finishing and for doing the rails. Search “sanding” and “polishing”
Having just commented on your shaping video, it is good you are asking questions about sanding an glassing. Nj surfer is correct in general; however, do not use “higher rpms” for “higher grits” or you will glaze the paper and end up with a very poor sand/polish. There is a technique that involves proper use of rpm’s and trigger use, and that is your helpful hint of the day.
Ok here is another thing Im real curious about. Is it better to have a heavier sander as opposed to a lighter one? I hear people are saying that a heavier sander weighs the tool down making you focus more energy on moving the pad faster on the board. Others say that a lighter sander makes you have more control over it. I have a real heavy sander.
It really depends on the task. Lighter tools can offer more control; however, sometimes ‘big bertha’ is the tool, like when polishing out real glosses on surfboards, and watch out for glass on’s. Bertha is the name of my 9’’ 6,000 rpm milwaukee grinder w/o speed controls. Everyday use will make even Pop-eye cower when he sees the size of your forearms…
Haha thats good ghettorat. To be honest I do feel more comfortable with my heavy sander. It wont all of sudden jerk and spin off. Its pretty smooth for me because Im starting to feel for the right amount of pressure to use on it. In between taking off enough glass and not creating crazy wheelmarks.
1) No cuts, glass when wet will stretch any way you want. You'd be amazed how will it flexes. The only cuts needed are at tip or or tail......and i mean the very tip or tail.
2) cut it in a bi fold with flap, or no flap. You need to take material out of the folds to have it lay down properly. it looks like a peace sign when cut.
3) Yes that will work
4) people don't sand there hot coats enough. Keep sanding to remove all the wobbles and excessive weight.
You don’t speed up the sander with higher grit paper? Nobody ever taught me how to use a sander, so I don’t know what everybody else does. All I know is I can increase rpms with higher grits and move through them faster without risking too much damage. It’s just a time saver. Move the sander faster, increase the rpms, cover more ground in less time.
I have the same sander in a variable speed. I think mine goes from 0-6. That’s 6,000 rpms, right? I go to about 1,000 with the rough stuff, about 3,000 with the fine stuff, and really rev it up with the bonnetts and polishes.
Howzit tg, Stop and go get the damascus glassing video before you proceed. Asking questions and reading about glassing is not the answer for you. You need to at least watch a pro like Cleanlines glass and watch that video till it is imbedded in your brain then go for it. In the end doing it is the only way to learn but a video is the next best thing. Aloha,Kokua
Having just stuffed up an EPS blank trying to fill it with Q-cel and epoxy (but that’s a whole other thread on its own), I’m not a good person to chime in.
But anyway - my mentor suggested to balance the sander weight by holding around the body up near the head and use the other hand down near the trigger to control angle. Seems to have cured my sand through habit. Was his good advice or do you use the handles?
NJ, when sanding higher grits at higher rpms the sander starts to act like a hover-craft. The heat produced can cause the resin-dust to glaze the sandpaper, and this glaze will scratch producing wheel marks. If you trigger the sander on and off, think of it kind of like a broom sweeping the dust off, and by triggering the heat caused by friction is reduced, and the dust is ejected more cleanly. Now this does not apply if the higher grits are used while wet sanding. If your doing it in an environment with water flowing the friction is reduced as well as the sanding residue.
I get what your saying… but I don’t think I’m coordinated enough to do it! Ha!
What kind of motion do you do with the sander? I take passes parallel with the stringer, up and down the board, using mostly the 2-3 o’clock part of the pad. The pad is almost flat, but most of the pressure is on that 2-3 o’clock zone of the pad. If I’m triggering the sander, when do I squeeze? Is it coordinated with a push or pull of the sander?
NJ, 3000 rpms is not fast that is in the middle as far as speeds are concerned for surfboard building tasks- using the color coding off the power pads as a benchmark. What the triggering effect does essentially sweeps the dust as you go along, it breaks the resin surface layer away from the surface to be sanded. After you cover the whole board this way you can open it up more on the rpm’s. Imagine sweeping as the metaphor, for when you drag a broom in one continual direction it tends to just spread the dust evenly over the floor. Triggering will help move the dust away like the motion of sweeping. Pads should be flat, but the 2-3 o’clock zone can offer control, if that makes you more comfortable. Do what feels comfortable, if it is working for you. If not it will show in your work, and by then its too late.