Can "Claptrap" be used to mean low quality?

Solution 1:

The Online Etymology Dictionary gives for claptrap:

c.1730, "trick to 'catch' applause," a stage term; from clap (v.) + trap (n.). Extended sense of "cheap, showy language" is from 1819; hence "nonsense, rubbish."

The later meaning refers to a device for generating applause, analogous to canned laughter. There is not much distance from there, referring to something unearned and thus empty, to worthless, and thence to trash or something tumbledown or hardscrabble. A Google Books search turns up, for example,

From The Argosy 121(3), 1920:

But when Temple had taken Jean his wife to see the completed house she recoiled horror-stricken. La Salle, following them, came in hurriedly, but Jean had seen the truth: for the house of her husband's dream was a house of fraud in a marsh, actually a claptrap house, a cheaply built shell in a desert waste land.

Earlier, from 1872 Congressional testimony:

There was another consignment of coal on this ship, which was being weighed by another city weighter in some kind of a patent clap-trap coal-weighing machine, and I had seen him take his weights.

I had always assumed— incorrectly it seems— that claptrap was some sort of reference to clapboards, sawn, untreated wooden boards used for exterior cladding of a house, which turn gray with weathering and take on a dull or cheap appearance. And low-grade buildings may be known as rat-traps or firetraps. Perhaps I am not the only one. In any case, its sense as a reference to something dilapidated or ramshackle is well-established in American English. There was a favorite Lucille Bluth double entendre from the sitcom Arrested Development:

How am I supposed to find someone willing to go into that musty old claptrap?

Solution 2:

In early 18th century England a clap trap was a cheap, showy line guaranteed to 'trap a clap' from the audience.

• Finally, it came to mean any kind of nonsense or rubbish.

(alpha dictionary)

Solution 3:

To give a further sense of how claptrap was used in the eighteenth and nineteenth centuries, I offer these instances as supplements to those given in choster's excellent answer. From a review of "Othello acted by gentlemen and ladies, &C." in The Scots Magazine (March 1751):

The gentlemen and ladies who acted, were sumptuously dressed and with great propriety. They were all extremely perfect in their parts, gracefully proper in their deportment, not in the least offensive in their action ; and, what is seldom observed by the best experienced actors, they were, through the play, constant in their attention, and characteristical in their manners. Their elocution was natural and easy ; free from the whine, the mouthing, the cant, the claptrap trick, and the false consequence, so often hackneyed upon stage.

And from Edmund Burke, Thoughts on the Cause of the Present Discontents (1775):

The members [of a political party] seek by every just method to get their party into power so that their plans may be executed. Such rivalry is easily distinguishable from a mean, selfish struggle for place and emolument. The opponents of party frequently parade as a virtue that they support "not men but measures." This is the veriest claptrap—a device to get loose from honourable engagements ; as in the case of a man who deserts his party when it loses power, and avers that he is supporting measures.

In the first instance claptrap appears in its original sense as a trick to capture applause; in Burke's remarks, it appears in the figurative sense of verbal hogwash. The distance between claptrap in the sense of "balderdash" and claptrap in the sense of something inferior, half-baked, or shoddy may not seem very far, but the earliest instances of claptrap in the latter sense don't begin to appear in Google Books search results until the middle decades of the nineteenth century. From Dialogues of the [Railway] Gauges (1846):

NARROW GAUGE. Be that as it may, not one of the plans you [Broad Gauge] propose is possible. They all involve great delay, great expense in working, great outlay for stock, all the risks of temporary fastenings, and a degree of uniformity in the construction of carriages and waggons throughout the kingdom that is unattainable. In short, they are nothing but claptrap expedients to stave off the only effectual remedy—uniformity of gauge.

The claptrap expedients in the argument between railway gauges are not different in character from the claptrap vessels in the OP's question—poorly conceived, ill suited to their task, and likely to fail in their essential function.