DCP’s Blog

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Restoration of Vintage Machines

Restoration of Vintage Woodworking Machines (IV) – dissemble/lubricate/assemble

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The first thing I would do before dissemble a vintage machine, after unloading it into my shop, is to print out a machine manual and a part list with the drawings of the machine. The machine manual and part list can be found at http://vintagemachinery.org.

I would dissemble the machine and compare it against the drawings. This will help me identify any missing parts and also help me understand how the parts are assembled together. I also would label every part that is taken off from the machine and store them into a plastic bag. In addition, I took  pictures during dissembling.

For nuts/bolts that are hard to turn, I use WD 40 or Blaster Penetrating Catalyst. To lubricate, I use machine lub oil for general lubrication. On my jointer, the threads on the machine lead screw are smashed. I used dies to clean the threads.

 

Below are a picture of the dissembled jointer and a picture after restoration (I am too lazy to re-paint it, BTW):

Restoration of Vintage Machines

Restoration of Vintage Woodworking Machines (III) – transportation

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After winning an auction, usually it is the buyer’s responsibility to load the machine from the seller’s place and haul it back to the buyer’s shop (transportation). Sometimes, the seller is even located in another city. For example, I have transported a Powermatic 66 tablesaw from San Antonio which is a 3-hour drive (one way).

It would be convenient to use a truck for this purpose; if not, you can rent a U-Hall trailer (with a ramp), and in this case your vehicle obviously must be able to haul the trailer. If you are lucky, the folks at the seller’s place have a means to help load the machine into the trailer (for example, use a forklift). If this is not an option, you still could dissemble the machine into manageable pieces and load the parts into the trailer. Remember that those vintage machines could weight 300-500lb

After loading it, the machine has to be secured in the trailer or truck bed; the easiest way I found is to use ratchet tie-downs. Those sold by Harbor Freight are actually pretty good for the price (disclaimer: I am not affiliated with Harbor Freight by any means, except being a customer with them).

Haul-Master® 62818 1000 lb. Capacity 1-1/2 in. x 10 ft. Ratcheting Tie Down Set of 4Haul-Master® 62258 700 lb. Capacity 1-1/4 in. x 16 ft. Ratcheting Tie Downs 2 PcHere is a picture of my PM 66 tablesaw tied down to a trailer:

Here is a picture of my jointer secured on a trailer:

After arriving my garage, to unload the machine from the trailer, I used a hand truck. I first remove the parts that can be easily taken off, for example, tablesaw top, jointer fence, etc… then tilting the machine body against the hand truck. All the transportation and unloading were done by myself alone.

Restoration of Vintage Machines

Restoration of Vintage Woodworking Machines (II) – Identifying Old Machines

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I usually prefer vintage woodworking machines auctioned by local schools. Through talking to people working in local schools, I found that the primary reasons that those machines are auctioned is because the school purchased newer equipment, or the woodworking program is terminated and the machines become no use. This generally means that the auctioned machines are still functioning. Another advantage of purchasing from the schools is that the schools would not use the machines as hard as a commercial shop; they even do not run the machines every day; the machines are not worn out.

However, what could happen to those machine is that some small parts are missing (abused by school kids); thus part of the restoration is to find the missing parts.

Note that I usually do not buy vintage machines from the Craigslist. My experience is that the old machines on the Craigslist are either too expensive or the machines that I like are hard to find.

The auction site usually puts very limited information of the machine on the auction page; you need to find the specs of the machine. I find a few webpages are extremely helpful:

Old Woodworking Machines (http://owwm.org)

VintageMachinery.org (http://vintagemachinery.org/)

It seems the organizers of above websites are actually the same bunch of people.  The first website focuses on the user discussion (forum based); the second is more like a database for collecting all the documents. I use the first website to ask a specific question that I could not find an answer; I use the second website to find the specifications of the machines.

Restoration of Vintage Machines

Restoration of Old Woodworking Machine (I)

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I have several power tools that are old vintage machines. They include: (1) Rockwell drill press (1950s), (2) powermatic tablesaw 66 (1960s), (3) powermatic jointer (1970s), (4) Powermatic planer (1970s).

I love old woodworking machines; out of the vintage machines that were manufactured in last century, I prefer the ones made around 1970s. A couple of reasons for the preference: (1) 1970s was before the finite element analysis (FEA) becomes popular. The FEA is a modern and accurate computational method for calculating structural stress of a machine. This method allows for a significant material (steel) saving for the design. However, before this method becomes a mainstream technology, engineers had use empirical equations and big safety factors in the design, which results in heavy cast iron and extra materials. So we often see the machines made at that era are heavier and last forever. (2) 1970s is before the exodus of U.S. manufacturing. This is not saying stuff made in Asia is no good; but we do notice the decline of the quality of those made from overseas. (Remember the primary objective of shifting the manufacturing to those low-cost center is to reduce cost, which is often at the expense of product quality.

There are a few highlights in buying vintage machinery. One is that the purchase price is generally a lot lower; people usually sell these old iron at a fraction of the price of a brand new product. The second point is that there is a lot of challenges in loading/transportation/unloading these machines. The last point is that, to use them, restoration is usually necessary.   In next blog posts, I will discuss the last two points in more details.

Miscellaneous

Woodworkers’ Club of Houston

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我是休斯顿木工俱乐部的一员,.俱乐部作为休斯顿地区最大的木工俱乐部,大概有300-400个成员,在每个月的第二个星期六都聚会和交流。成员相互介绍木工经验,交流木工信息,展示自己的木工作品,非常有意思。俱乐部还常常邀请木工界的专家举行讲座。比如下周要邀请 Matt Cremona。

这个组织有几十年的历史了。有正式的组织结构, 包括management team, 董事会。每年都有选举来决定董事会成员和management team. 这个俱乐部是一个美国注册的非营利组织。俱乐部下面又分为很多小的兴趣小组, 包括手动工具兴趣小组,家具制作兴趣小组, 数控加工兴趣小组,伐木/干木兴趣小组等等; 这些小组每个月也有聚会。

我是俱乐部比较年轻的成员。大多数俱乐部成员都已白发苍苍,这让我感觉不错:)

Fine WoodWorking

Fengjie’s Benches

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Fengjie’s Benches

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Fengjie saw the bench I made next to the countertop in our house, and asks me to build two for her. Knowing Fengjie for many years I understand her needs; she frequently has parties and friends coming to visit; the sitting space becomes an issue.

The first bench I made for her is exactly the same design as the one used for the countertop in our house, so she can make better use of her countertop.

 

The second bench is actually made for matching her formal dinner table. This bench has dimensions of 17.5″ height, 58″ length, and 15″ width. It is made of oak. The top coat is wipe-on polyurethane. Because the span between the legs is fairly long, I had two stretchers between the legs; to make sure the bench has enough strength, on top of the mortise/tenon joints, I put dowels through the MT joint to enhance the joinery.

Fine WoodWorking

Counter Top Bench

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My SWMBO (She Who Must Be Obeyed) asks me to build a bench for our island kitchen countertop. The countertop has a side (toward the breakfast area) that is never really been used. My wife suggests a long bench that can be placed next to it, so we can better use the space.

I started out by designing the bench in a 3D design software; made sure my SWMBO likes it; purchased black walnut lumbers (more than $7/board-ft, ouch!) from a local lumber store. Here it goes:

The below picture shows the kids having a breakfast; they prefer to use the bench more than the formal breakfast table now; maybe it is just sooner to eat when the mommy gets the meals ready:)

Fine WoodWorking

Kid’s study desk

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My buddy Oscar asked me to make a small study desk for his two young daughters; one is 6 years and the other is 4 years old. Commercial study desks, primarily designed for an adult’s height, are too tall for the kids. On the other hand, those desks for young kids, sold by Amazon or IKEA, are pretty much made by particle boards or ply wood, which obviously SUCKS.

What Oscar wants is a very simple design, but made by solid wood. He does not want additional features even like drawers or build-in electrical outlet. The desk must be big enough for the daughters to sit at the both sides.

So I used hard maple and oak. The table is 24 inch tall, which perfectly fits the height of their daughters at this age. The aprons on the table have curves that allows extra room for kids’ legs as they grow.

The table top is 3 ft long by 2ft wide; this is pretty wide as compared to the length, per Oscar’s request (two daughters can sits on the both sides at the same time). The tabletop uses a classic solid wood top construction, with end caps at the both ends. These end caps are designed for compensating the wood expansion (a.k.a. wood movement) across the width of the table top. The end cap is only glued at the middle, with pins towards the ends allowing the wood movement.

Woodworking Technology

油漆 (II)

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接着聊家具的油漆。

油漆的选择对家具的外观有着决定性的影响。但是油漆产品非常多,市场竞争激烈;为了促销,厂家常常给产品起非常让人疑惑的名字,混淆了油漆的种类,造成了使用者的困惑。

如果我们对比百年前的家具(都有用类似的榫卯结构为架构), 现代家具的主要技术进步包括:(1)现代合成油漆技术;(2)人造合成木板材(三合板,纤维板);(3)router和数控机床加工。人造合成木板材极大的降低了原材料成本(例如IKEA);router 和数控机床提高了木材加工效率,使曲面加工成为一道相对简单的工序;油漆技术是随着现代合成化工技术的进步而有了显著的提高。

现在,人造合成木板材技术以及数控加工技术已经相对成熟。然而油漆产品到现在依然推陈出新,基本每年在市场上都有新产品,而且产品愈来愈好。

百年前的家具,很多都是不上漆;法国家具上虫漆(从虫子身上提炼出来的);中国古代上桐油,或者上lacquer (真漆, 一种从树上提炼出来的漆)。 这些漆都是挥发性的,对木头的保护其实不强,而且每隔一段时间还要再涂一次。现代的varnish是涂上之后和氧气发生化学反应 (curing),然后固化,对家具形成很好的保护。

家具厂的主要用漆是lacquer(这个和古代的lacquer很不一样), 主要的优点包括容易喷涂,容易加色,短时间固化(提高效率)。缺点就是易燃,易爆,需要非常昂贵的喷漆车间。

木工爱好者主要用漆包括varnish和polyurethane. 尤其是polyurethane, 经常用做地板漆,非常耐磨损。值得注意的是,因为油漆市场很大,各个厂家为了推销自己的产品,常常给产品起一个非常市场化的名字, 比如Watco Danish Oil, 根本就不是丹麦油,而是一种polyurethane varnish; 这也直接造成了大家选择油漆时的困惑。

现代油漆是基于是油性的,也就是主要的溶剂是以油为主。进入2000年之后,随着环保意识的提高和环保立法的确立,以水做溶剂的油漆开始出现并且进入主流市场,以前质量比不上油性漆,但是最近几年愈来愈好,基本跟油性漆旗鼓相当,现在所有主流油漆制造商都有水溶性油漆产品。

我喜欢用的漆包括水溶性的EM 6000(Target Coatings); 我也喜欢用varnish,包括general finishes的arm-r-seal.

Woodworking Technology

木工油漆

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常听到朋友问起,你做家具用什么油漆,或者是上几层油漆? 这其实是一个非常难回答的问题,因为这取决于木料, 以及家具使用环境要求。

严格的讲,家具最外表面的涂层 (英文叫finish),不能笼统的叫油漆 (paint), 因为油漆是不透光的。而我们木工爱好者常用到的清漆(无色透明的油漆),包括varnish (家具工厂喜欢上lacquer). varnish是一种由人工树脂, 油脂,和溶剂合成的粘性液体, 清漆里面的油脂遇到氧气,就会开始固化,在家具的外表面形成一种很硬的保护膜. 一般而言,清漆是家具涂层最外面的一层,所以要求耐磨损,有一定的抗化学试剂的能力(比如不小心酒精泼上去);而且要阻挡水分进入木料(关于这一点,以后会详细的介绍)。而且一般清漆要涂上3-5层,这是为了保证清漆的足够的厚度。

清漆没有颜色,那我们家里的家具为啥都有颜色?这是因为在涂上清漆之前,家具会先上色 (stain)。两种化学上色的化工原料: 色素(dye)和顏料(pigment), 对于我们木工业余爱好者而言,二者主要区别是分子的大小。色素比颜料小很多,因此色素进入木头比较深。但是色素没有颜料抵抗紫外光能力强,时间久了,色素容易褪色。

我们常看到很多家具有非常绚丽的木纹,其实这也是通过化学试剂强化的。常用到的化学油脂包括水压亚麻籽油 (boiled linseed oil)或者桐油(tung oil);木纹细胞对油的吸收以及反应跟普通的木头细胞非常不同;在光的反射下,木纹会显得特别的炫丽。

以上是最基本的涂层要求,而实际比这些要复杂太多;比如,因为家具用的木料不同,常常要选择不同的化学试剂,这些化学试剂形成的涂层之间常常不能粘合的很好,这又要求有底漆 (washcoat)来帮助它们粘合,比如用虫漆 (shellac). 再比如专业的家具厂,为了家具好看,不止涂一道颜色,这样能够增加色彩的深度。最终的结果是非常复杂的上涂料的工艺过程,6-7道涂层很常见,十几道涂层的也都有可能。

Bob Flexner的书中(Wood Finishing – How to Select and Apply the Right Finish)对木工油漆涂层有非常好的示意图:

对于家具的使用环境,油漆要求也不同,户外油漆和室内地板油漆成分有很大的不同。当我们选择油漆时,首先的就是看户外用漆,还是室内用漆。