Tools for Refinishing

[krash]

About to take on a project to refurbish/refinish an Epoxy SUP.. the board has lots of scuffs chips, and scratches in the paint and top coats, but not really thru the glass into the foam. May also add a leash plug or two, handle, and fin box.

Looking for some recommendations and/or suggestions for a sander/polisher and router for a one time DIY'er.

Which a better choice for DIY a palm or angle type sander ?

Is a light weight small plunge router good enough and will I need special templates for leash plugs or fin box ?

[PonoBill]

Slippery slope asking this crowd, especially me. Talldude will have you adding a ceiling dust extractor. When you take on a project it's never one time--the first leads to the second, like eating pistachios. If you're going to BUY tools get decent ones. You can spend a grand plus on a Festool sander, but instead buy a big 7" angle grinder, the kind they use at body shops, and get a Flexpad: https://www.flexpadusa.com/  The big guys are surprisingly cheap from Harbor Freight, garage sales or craigslist. I have an expensive one that I've owned forever and a cheap harbor freight one which is the one I reach for. Half the weight, variable speed, works fine three years later. I think it was 69 bucks. Oops. looked it up. 43 bucks.
https://www.harborfreight.com/7-in-11-amp-heavy-duty-angle-grinder-62766.html

A little router is actually preferable for most work on boards. I've got three routers, 99 percent of the surfboard work I do is with a very simple, dinky adjustable base trim router I picked up at a garage sale. Weighs very little, dangerous as hell since there's no guard and you hold it by the motor, but I can see what I'm doing and it works fine. You can make your own templates or just practice a bit and follow lines. I bought router number three to do a better job with templates and discovered it's a pain in the ass unless you're doing them all the time. Harbor freight has one like mine for 30 bucks. https://www.harborfreight.com/14-in-24-amp-trim-router-62659.html

[eDUBz]

In that case Harbor freight is your friend. You can get a 7” DeWalt Variable speed sander/polisher to tackle this one time job then just use it for your vehicles to polish. Technically you can Refinish the board by hand with a $hit load of sanding and time. Block sanders and razors.

[TallDude]

You definitely want a sander with a flexible foam disk base so it can bend and conform to the surface. Surfboards / SUPs have curved surfaces where as a wood surface would typically be flat. Felt pad based sanders like palm sanders are perfect for flat work, but not a good choice for curved surfaces. With epoxy you want a lower speed as well. High speed sanders will heat the epoxy surface up to quickly. Too high of speed and the epoxy actually starts to melt on to your sand paper, clogging it up. Additionally, too much heat can cause the foam below the sanded area to melt and /or de-laminate from the glass. For this reason, you never want to sand one spot continuously. It's better to use a heavier grit like 80 at first, to remove some paint and cut into the hot coat. Then switch to a 200 grit, to get to your 'prep'd for patching' level. I use a 7" Makita variable disk sander / polisher (pretty much the same as what eDUBz and Pono mentioned) with a yellow foam disk from https://fiberglasssource.com/collections/sanding-pads/products/flexpad-sanding-pad-8-inch-soft-density-yellow-white.

Using a power disk sander takes some / a lot of skill. I had a power sander in my hands before I hit my teens, so It's hard for me to gauge what kind of learning curve someone without carpentry skills would had to go through. The hand sander takes a little more effort and time, but is a much safer and cheaper method. It takes hook-loop standard sanding pads. https://www.amazon.com/Sungold-Abrasives-98910-Sanding-Block/dp/B012SWPZ2U/ref=pd_lpo_vtph_263_tr_t_2?_encoding=UTF8&psc=1&refRID=YTW70A33FVVSNDM1BEFS
I probably use this more than any other sander I have. Less risk of overheating an area, and is the best thing for the rounded rail areas of the board. If you don't know what you are doing with a power disk sander, you can cause more damage that you had initially. Definitely don't use the power sander on the rails unless you are very skilled with it.

You have to change sanding disks way more often than you think. The epoxy clogs up the sand paper quickly (within minutes), but the epoxy residue is clear so the sand paper looks still good to the naked eye. You'll know how clogged it is by the how much better a new disk sands.

You can use Bondo to fill the pits and recesses left from the chipped out paint areas. Larger dings will require an epoxy additive like Cabosil. After you sand, drag a piece of tape (sticky side down) over the area to be painted or epoxied (works like a tack cloth) to rid the area of all small dust particles. If you plan to paint the bottom of the board, you should consider a 2K clear coat over the paint on at least the bottom. Most glassed boards use a pigmented epoxy for the bottom color and paint the top.

Sounds like a fun project.