Big Boy Ultra Fine Body Filler

First time using any kind of body filler to fill in two indicator 'holes' where my old indicators used to mount to on my motorcycle's ABS body panels. The mounting spots for the front indicators were about 20mm x 30mm with a short recess before curving out into the rest of the panel. I had re-wired the headlight 'aux/running' rights to be indicators by swapping the W5W bulbs for amber LED W5W units and swapping some cables so it meant I no longer needed the bulky stalk indicators and could fill in the hole. This stuff worked just as I had hoped. I was going to use some mouldable glue like 'Sugru' however I thought this would be a more permanent and neater solution. The only difficulty I had is that I didn't want to use the entire tub at once as I didn't need that much. I only needed to use about 1/10th whats in the tub but theres no measurements to how much hardener I need per random amount of whats in the tub. I did it by eye and I appeared to have got it right as it hardened just fine. It stinks, as a warning. It lets of a lot of vapour and you wanna do this outside in a well ventilated area. Mask up the area you're working with as you don't want this stuff to cure on any surface you don't want to get ruined. When it was fully cured (I left it for 2 days, this wasn't required I was just able to) it was time to sand it down to match the curvature of the panel. It's super satisfying and so so easy to sand this material as it just turns into powder and doesn't clog up sandpaper. Once finished, it's immediately ready for paint and it takes a coat super well. The end results were far from perfect, as I said this was my first time, I wasn't expecting a bodyshop finish. Close up, you can tell, but that wasn't my goal I just wanted to fill them in. I'll edit my review if they crack or fall out as it does say on the tin that it *may* not stick to some plastics. However it felt very firm and didnt move at all during sanding. In summary, this stuff is great to work with and has amazing sanding properties. I highly recommend using this stuff instead of mouldable glue as you'll get a much better finish. However, be prepared as it's harder to do and you need much more prep beforehand.

If, like me, you want a fast drying, easily appliable and a good hard finnish to work with, this is as good as it gets. Has simply given me a solution to the work I want to complete.

Just to be clear, this product is generally very good. I am using it to fill holes and gouges in an old table I'm upcycling and it sticks perfectly, sands down to a lovely finish, and takes paint nicely. I highly recommend it for woodworking. However...the mixing instructions are useless to anyone who is not using the whole tin in one mix. To be fair I can imagine that people using this for car body repairs do just that. Let me paraphrase the mixing instructions - "mix and equal ratio of filler and hardener (eg. half a tin of filler to half a tube of hardener)". I laughed out loud at that instruction because the tin of filler is about fifteen times bigger than the tub of hardener! And the tube of hardener is opaque plastic - there's no way to tell how much is in there. I thought "this is easy...I can just weigh them out on a digital kitchen scale". But no...the tin of filler is measured in volume units (250 ml) and the tube of hardener is in weight units (15g). There's no way to easily measure out on the scales. So...my first batch set in about 90 seconds - probably because I added too much hardener and also it was baking hot in the room. My second batch was much better. I left the tin in my wine fridge (12 degrees C) overnight and used a bit less hardener. It went rubbery in 5 mins (at which point you can't use it anymore) and was hard enough to sand in 10-15 mins. As I said, I'm very pleased with the finish, but I suspect I'm going to run out of hardener much quicker than I run out of filler, and better instructions would have helped to avoid that.

This is difficult to be critical of. It's a great filler, it's just about the only one I'd recommend for 3D printing or general use, can confirm I've used it with eSun PLA+ with great success. Tried several brands and technologies including AK, Vallejo, Toupret, and this came out on top. I can't speak for the other variants that Silverhook makes however. It sands real smooth and doesn't suffer from chipping provided the surfaces are prepared beforehand, adheres very well, very fine consistency too. I fully understand that 3D prints are not the intended use but it does work, only too fast. The solution to this is to do it in lots of small successive batches. For fellow 3D printing enthusiasts I've written some directions for use below, assuming the print is fresh off the printer: 1. Buy generic Chinese sanding blocks (orange, blue, grey multipacks, 24 pack was the best value for me) and use from 60 to 220 grit to reduce print lines, keep sanding until the surface looks somewhat fuzzy. 2. Buy generic chinese sanding PADS (red felt-backed, for attaching to power tools usually in an 18 pack) and use with a black and decker mouse until you're satisfied with the surface smoothness. 3. Buy some bulk packs of clear pill measuring cups (50pk ~£5), and bamboo wax jumbo lollipop sticks (1000pk £10~15). 4. Decant and stir up a very small batch say 10ml filler, to 1ml red catalyst (a pea sized amount). 5. Mix it extremely thoroughly, fold and scrape, make sure none is left unmixed as it simply won't cure. You can tell by the shade of colour, uncured is lighter. 6. Use a new lollipop stick to spatula it on, and add slightly more than you think you need. You can build up coats instead but there's really no point. 7. Use generic Chinese sanding BLOCKS to take off the bulk of the excess, then use the PADS with a black and decker mouse until the surface is silky smooth. 8. Prime with Jenolite and polish with the finest grade sanding pad. Best of luck!

Overall this is really good stuff. It comes with hardener and also a small flat scraper/smoother, about half the size of the normal ones. The lid can be a tricky to get off, but take your time with a flat head screw driver and work your way around the can jimmying and itll come free. It really stinks as filler does. I was mixing about a teaspoon at a time with a drop of harderner, it goes off quite quickly, maybe 2 mins tops working time. I could sand it after about 10-15 mins. Sanded nicely with some sandpaper- mainly 240 and 320 i used. It makes nice sharp edges if you work it right. Painted over with primer and it looks good! Adhered to the bare metal on a car body very well.

This filler is easy to sand and gives a superbly smooth finish. I suggest using wet-and-dry with a little soap and working through the grades to get the easiest and best results, although it comes out smooth even with dry sanding. On a hot day, it will not give a long working time if you follow the hardener ratio stated by the maker, so it will set perfectly well with a fraction of that, but can take an hour or two if you got too light on it. Even at 20C I find that I never need more than half of what the makers suggest as the amount of hardener. The product takes paint well even without a primer or undercoat, but for longest lasting results, I suggest that those should be used. Mix small amounts ... it is easy to apply more if needed, rather than see it wasted because it went off be fore you could get it applied. One or two practice mixes before doing serious work, will give you a feel for it, even if you have used such as P38 before, because this is faster setting than P38. I have not given any rating for durability because I first used it only a week ago, so time will tell.

Decent quality filler that hardens off well & is not too bad to sand down. Expensive really for the amount but at least it shouldn't go off

Strong and easy to use. Used it to hold down a metal foot for a steps handrail where the bolts had cracked the stone.