There have been a few discussions on this in the archives. In gloss, hotcoat and sanding threads I often feel the taping off stage is glossed over (excuse the pun).
Anyone care to share? Where do you lay the tape for gloss? Different position to fill coat?
I often get little voids around the tape line, no matter how carefully i seem to lay tape and clean of any remaining adhesive.
For the fill coat, I’m taping off so I can get a little bead of resin around the hard edges in the tail area. For the gloss, I’m pretty much taping of at mid rail the whole way around. This might not be the “right” way to do it, but it works for me.
Mid--rail for both. With exception of the tail if you desire to build a sharp edge. I don't know what you are referring to when you speak of voids. Make sure your tape is pressed hard. I use a "thimble" to press tape on a lam or hotcoat. Wall paper seam rollers work well also. If you are getting tape residue; You need to step up to a higher quality tape such as 3M 233+. When I am doing a hotcoat or gloss I always make sure I make a pass around the rail to make sure I've got resin down on the tape. Spread the resin around, cross-stroke and then a final nose to tail lay off with a sweep around the rail to lay off and remove excess resin on the rail and tape. I use 1 1/2" tape as it is easier to get the tape to hang down straight so that excess resin drains straight down and doesn't drip around the rail and on to the oppostie side. I don't like sanding or knocking down drips that shouldn't have been there to begin with .
"No secret magic in a tape off". Straight ahead. I think if I were doing EPS foam and taping off for paint or a cutlap I would try "blue painters tape". I think we discussed this before in another thread. It was mentioned that almost anything will stick to EPS. If you are having trouble with residue from 3M 233 try the blue tape. Just wipe the rail down with a tack cloth and make sure it sticks, so you don't have resin running under the tape and onto the opposite side. I've taped off a rail before with blue tape, turned around to get my resin and brush went back to the board to find my tape laying on the shop floor.
Cheers guys.
Where is the mid-point of the rail through the tail where there is no bottom rail? Flush with the bottom? Half way up the top rail?
When taping the 2nd side, do you leave a little overlap on the resin line, or tape right up to the edge?
Does anyone create resin dams during sanding coats in pointy bits like noses and tails to give extra protection?
Sorry if this seems obvious to everyone. My fills and glosses aren’t terrible, but I always seem to spend more time cleaning up and sanding around tape lines than I feel I should. Be nice to know how its done for minimum fuss.
Didn't think it would be that hard to figure out. Follow the rail line(edge) in the tail area. If you want a hard resin edge allow your tape to creep up beyond the rail line beginning in the fin area. This will give you a "tape dam" to hold the hotcoat resin. If you can't do it with one continuous piece of tape, add another in the tail area. Press it down hard. Don't over-lap your tape onto the previously hotcoated side. Keep it right on the line.. Most pros only tape one side on the hotcoat. Your best bet just starting out is to tape both. Which means tape off twice for the hotcoat and twice for the gloss. Pretty simple really. If you are still having problems after this, you aren't doing something right. Hope that helps.
This is pretty close to how Bammbamm808 taught me to tape a shortboard hotcoat a few years back
One video is worth a thousand words. One continuos piece of tape, with a dam in the fin/tail area. Flipped out so the resin wont run around onto the otherside. The dam straight up to hold the resin for the hard edge. Always double check your tape before you start to spread that resin. Bueno
The video shows how most of us do it. Ironically, the problems I've had recently have involved sticky residue at the seam on the gloss coat using 3M 233+. I NEVER had that problem using blue painter's tape which is shunned by the pros. Go figure.
if you new at it
tape at the rail widest point
shoot it
flip it
retape so you have overlap resin
shoot it
sand it
resin dam it and
sand it
or
do it what ever way works for you
Anyone had any problem when taping off on deckfor glassing bottom on eps? Even when I seal the blank with epoxy/silica mix i get soem foam coming away with tape after cutting up to tape on lap. I use 3m tape - too sticky? This happens on dense foam also.
Thanks
jemski
Yes. I wonder if the high heat and humidity where i live means more gum is left than normal. I ALWAYS have to sort out residue.
Thanks for the replies and the video (Bud). This is also how I do it.
No secret magic in a tape off then 
JEMSKI… I’ve had that happen, too, but only along the cut edge itself. It never happens anywhere under the tape except along that line. I don’t worry about it. I just hit it with some lightweight spackle.
Aloha Tomway
Where you place your tape depends on a couple of things. If you machine down the tape seam (and you should) then you may like that seam to be deck side 1" or so above the middle of the rail when sanding. This allows you to machine the seam with the board laying flat on the racks. One of the big dramas in surfboard building is trying to sand the seams down and not go so far that you sand through to where weave shows. If you place the seam off of the peak of the rails curve on the less curvy deck side you may find it easier to sand without burning through as you will have a flatter area to spread the sanding over. To tape like this you may have to tape the board off from the “other” side as you may not be able to reach under that far. Try it… you’ll see what I mean.
If the board has hard edges all the way around then it may be better to tape just past the edge about 1/8" so that resin sags and builds at the edge as it drips. This will allow you to sand on the flat bottom and not right on the edge but still cut this build up, off and back to create more edge.
There are a couple of solutions to this problem. After the tape has been pulled and your ready to gloss the other side… try this. Lay tape centered over the resin seam and with your fingernail press the tape into the corner of the seam where you get the tape adhesive build up and voids. Then pull the tape up and do it again and again until you can see that the seam is clear of any tape residue.
Or… Make your first side tape line well below the peak of the rail (as noted above). After it cures, and before doing the second side, use a razor blade and breakdown the edge of the seam completely, flowing it back into the rest of the glossed and sanded areas. Then lightly hand sand with 400 grit … all the way from the razor bladed area, past the peak of the rail, to where you are going to tape the other side about 1" beyond the peak of the rail. Gloss as usual.
Now you won’t have any tape seam in which to get voids. And you will only have to sand down a single seam instead of a much larger double seam. PLUS… you will have a double gloss on the peak of the rail which is the primary area where burn throughs take place!
There’s that magic. Thanks Bill!
And just in the nick of time too. Off to do a gloss right now.
Your welcome tomway. Hope your glosses come out slick!